Programming-in-D-in-Chinese
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parameterflexibility.html

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<title>Variable Number of Parameters</title>
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<h4 style="margin: 1.25em 0.5em 0.5em 8px; padding: 0px; border: 0px; outline: 0px; font-size: 1.5em; vertical-align: baseline; background-color: transparent; font-family: sans-serif; font-weight: bold; color: rgb(0, 0, 51); font-style: normal; font-variant: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
Variable Number of Parameters</h4>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
This chapter covers two D features that bring flexibility on parameters when
calling functions:</p>
<ul style="margin: 0.5em 1em 1em; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
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	Default parameter values</li>
	<li style="margin: 0.5em 0px 0px 1em; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; background-position: initial initial; background-repeat: initial initial;">
	Variadic functions</li>
</ul>
<h5 style="margin: 1.25em 0.5em 0.5em 8px; padding: 0px; border: 0px; outline: 0px; font-size: 1.25em; vertical-align: baseline; background-color: transparent; font-family: sans-serif; font-weight: bold; color: rgb(0, 0, 51); font-style: normal; font-variant: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
Default parameter values</h5>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
A convenience with function parameters is the ability to specify default values
for them. This is similar to the default initial values of struct members.</p>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
Some of the parameters of some functions are called mostly by the same values.
To see an example of this, let&#39;s consider a function that prints the elements of
an associative array of type<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">string[string]</code>.
Let&#39;s assume that the function takes the separator characters as parameters as
well:</p>
<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;"><span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">void</span> printAA(<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">in</span> <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">char</span>[] title,
             <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">in</span> string[string] aa,
             <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">in</span> <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">char</span>[] keySeparator,
             <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">in</span> <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">char</span>[] elementSeparator)
{
    writeln(<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;-- &quot;</span>, title, <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot; --&quot;</span>);

    <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">auto</span> keys = aa.keys.sort;

    <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">foreach</span> (i, key; keys) {
        <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: green; background-position: initial initial; background-repeat: initial initial;">// No separator before the first element
</span>        <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">if</span> (i != 0) {
            write(elementSeparator);
        }

        write(key, keySeparator, aa[key]);
    }

    writeln();
}
</pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
That function is being called below by<span class="Apple-converted-space">&nbsp;</span><span class="d_string" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;"><tt style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; background-position: initial initial; background-repeat: initial initial;">&quot;:&quot;</tt></span><span class="Apple-converted-space">&nbsp;</span>as
the key separator and<span class="Apple-converted-space">&nbsp;</span><span class="d_string" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;"><tt style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; background-position: initial initial; background-repeat: initial initial;">&quot;,
&quot;</tt></span><span class="Apple-converted-space">&nbsp;</span>as the element
separator:</p>
<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">    string[string] dictionary = [
        <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;blue&quot;</span>:<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;mavi&quot;</span>, <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;red&quot;</span>:<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;kırmızı&quot;</span>, <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;gray&quot;</span>:<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;gri&quot;</span> ];

    printAA(<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;Color Dictionary&quot;</span>, dictionary, <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;:&quot;</span>, <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;, &quot;</span>);
</pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
The output:</p>
<pre class="shell" style="margin: 0.5em 1em 1em; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 13px; vertical-align: baseline; background-color: rgb(224, 224, 224); font-weight: bold; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">-- Color Dictionary --
blue:mavi, gray:gri, red:kırmızı
</pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
If the separators are almost always going to be those two, they can be defined
with default values:</p>
<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;"><span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">void</span> printAA(<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">in</span> <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">char</span>[] title,
             <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">in</span> string[string] aa,
             <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">in</span> <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">char</span>[] keySeparator <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: rgb(255, 255, 136); background-position: initial initial; background-repeat: initial initial;">= <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;: &quot;</span></span>,
             <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">in</span> <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">char</span>[] elementSeparator <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: rgb(255, 255, 136); background-position: initial initial; background-repeat: initial initial;">= <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;, &quot;</span></span>)
{
    <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: green; background-position: initial initial; background-repeat: initial initial;">// ...
</span>}
</pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
Parameters with default values need not be specified when the function is
called:</p>
<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">    printAA(<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;Color Dictionary&quot;</span>,
            dictionary);  <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: green; background-position: initial initial; background-repeat: initial initial;">/* ← No separator specified. Both
                           *   parameters will get their
                           *   default values. */</span>
</pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
The parameter values can still be specified when needed, and not necessarily all
of them:</p>
<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">    printAA(<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;Color Dictionary&quot;</span>, dictionary<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: rgb(255, 255, 136); background-position: initial initial; background-repeat: initial initial;">, <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;=&quot;</span></span>);
</pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
The output:</p>
<pre class="shell" style="margin: 0.5em 1em 1em; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 13px; vertical-align: baseline; background-color: rgb(224, 224, 224); font-weight: bold; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">-- Color Dictionary --
blue=mavi, gray=gri, red=kırmızı
</pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
The following call specifies both of the parameters:</p>
<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">    printAA(<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;Color Dictionary&quot;</span>, dictionary<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: rgb(255, 255, 136); background-position: initial initial; background-repeat: initial initial;">, <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;=&quot;</span>, <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;\n&quot;</span></span>);
</pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
The output:</p>
<pre class="shell" style="margin: 0.5em 1em 1em; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 13px; vertical-align: baseline; background-color: rgb(224, 224, 224); font-weight: bold; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">-- Color Dictionary --
blue=mavi
gray=gri
red=kırmızı
</pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
Default values can only be defined for the parameters that are at the end of the
parameter list.</p>
<h5 style="margin: 1.25em 0.5em 0.5em 8px; padding: 0px; border: 0px; outline: 0px; font-size: 1.25em; vertical-align: baseline; background-color: transparent; font-family: sans-serif; font-weight: bold; color: rgb(0, 0, 51); font-style: normal; font-variant: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
Variadic functions</h5>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
Despite appearances, default parameter values do not change the number of
parameters that a function receives. For example, even though some parameters
may be assigned their default values,<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">printAA()</code><span class="Apple-converted-space">&nbsp;</span>always
takes four parameters and uses them according to its implementation.</p>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
The variadic functions feature on the other hand allows calling functions with
unspecified number of arguments. We have already been taking advantage of this
feature with functions like<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">writeln()</code>.<code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">writeln()</code><span class="Apple-converted-space">&nbsp;</span>can
be called with any number of arguments:</p>
<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">    writeln(
        <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;hello&quot;</span>, 7, <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;world&quot;</span>, 9.8 <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: green; background-position: initial initial; background-repeat: initial initial;">/*, and any number of other
                                  *  arguments as needed */</span>);
</pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
There are four ways of defining variadic functions in D:</p>
<ul style="margin: 0.5em 1em 1em; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
	<li style="margin: 0.5em 0px 0px 1em; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; background-position: initial initial; background-repeat: initial initial;">
	The feature that works only for functions that are marked as<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">extern
	&quot;C&quot;</code>. This feature defines the hidden<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">_argptr</code><span class="Apple-converted-space">&nbsp;</span>variable
	that is used for accessing the parameters. This book does not cover this
	feature partly because it is unsafe.</li>
	<li style="margin: 0.5em 0px 0px 1em; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; background-position: initial initial; background-repeat: initial initial;">
	The feature that works with regular D functions, which also uses the hidden<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">_argptr</code><span class="Apple-converted-space">&nbsp;</span>variable,
	as well as the<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">_arguments</code><span class="Apple-converted-space">&nbsp;</span>variable,
	the latter being of type<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">TypeInfo[]</code>.
	This book does not cover this feature as well both because it relies on<span class="Apple-converted-space">&nbsp;</span><i style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; background-position: initial initial; background-repeat: initial initial;">pointers</i>,
	which have not been covered yet, and because this feature can be used in
	unsafe ways as well.</li>
	<li style="margin: 0.5em 0px 0px 1em; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; background-position: initial initial; background-repeat: initial initial;">
	A safe feature with the limitation that the unspecified number of parameters
	must all be of the same type. This is the feature that is covered in this
	section.</li>
	<li style="margin: 0.5em 0px 0px 1em; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; background-position: initial initial; background-repeat: initial initial;">
	Unspecified number of template parameters. This feature will be explained
	later in the templates chapters.</li>
</ul>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
The parameters of variadic functions are passed to the function as a slice.
Variadic functions are defined with a single parameter of a specific type of
slice followed immediately by the<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">...</code><span class="Apple-converted-space">&nbsp;</span>characters:</p>
<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;"><span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">double</span> sum(<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">in</span> <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">double</span>[] numbers <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: rgb(255, 255, 136); background-position: initial initial; background-repeat: initial initial;">...</span>)
{
    <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">double</span> result = 0.0;

    <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">foreach</span> (number; numbers) {
        result += number;
    }

    <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">return</span> result;
}
</pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
That definition makes<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">sum()</code><span class="Apple-converted-space">&nbsp;</span>a
variadic function, meaning that it is able to receive any number of arguments as
long as they are<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">double</code><span class="Apple-converted-space">&nbsp;</span>or
any other type that can implicitly be convertible to<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">double</code>:</p>
<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">    writeln(sum(<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: rgb(255, 255, 136); background-position: initial initial; background-repeat: initial initial;">1.1, 2.2, 3.3</span>));
</pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
The single slice parameter and the<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">...</code><span class="Apple-converted-space">&nbsp;</span>characters
represent all of the arguments. For example, the slice would have five elements
if the function were called with five<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">double</code><span class="Apple-converted-space">&nbsp;</span>values.</p>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
In fact, the variable number of parameters can also be passed as a single slice:</p>
<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">    writeln(sum(<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: rgb(255, 255, 136); background-position: initial initial; background-repeat: initial initial;">[</span> 1.1, 2.2, 3.3 <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: rgb(255, 255, 136); background-position: initial initial; background-repeat: initial initial;">]</span>));    <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: green; background-position: initial initial; background-repeat: initial initial;">// same as above
</span></pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
Variadic functions can also have required parameters, which must be defined
first in the parameter list. For example, the following function prints an
unspecified number of parameters within parentheses. Although the function
leaves the number of the elements flexible, it requires that the parentheses are
always specified:</p>
<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;"><span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">char</span>[] parenthesize(
    <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">in</span> <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">char</span>[] opening,  <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: green; background-position: initial initial; background-repeat: initial initial;">// ← The first two parameters must be
</span>    <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">in</span> <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">char</span>[] closing,  <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: green; background-position: initial initial; background-repeat: initial initial;">//   specified when the function is called.
</span>    <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">in</span> <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">char</span>[][] words ...)  <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: green; background-position: initial initial; background-repeat: initial initial;">// ← Need not be specified
</span>{
    <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">char</span>[] result;

    <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">foreach</span> (word; words) {
        result ~= opening;
        result ~= word;
        result ~= closing;
    }

    <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">return</span> result;
}
</pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
The first two parameters are mandatory:</p>
<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">    parenthesize(<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;{&quot;</span>);     <span class="d_comment" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: green; background-position: initial initial; background-repeat: initial initial;">// ← <span class="d_hata" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: rgb(255, 64, 64); color: rgb(0, 0, 0); background-position: initial initial; background-repeat: initial initial;">compilation ERROR</span></span>
</pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
As long as the mandatory parameters are specified, the rest are optional:</p>
<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">    writeln(parenthesize(<span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;{&quot;</span>, <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;}&quot;</span>, <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;apple&quot;</span>, <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;pear&quot;</span>, <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: red; background-position: initial initial; background-repeat: initial initial;">&quot;banana&quot;</span>));
</pre>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
The output:</p>
<pre class="shell" style="margin: 0.5em 1em 1em; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 13px; vertical-align: baseline; background-color: rgb(224, 224, 224); font-weight: bold; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">{apple}{pear}{banana}
</pre>
<h5 style="margin: 1.25em 0.5em 0.5em 8px; padding: 0px; border: 0px; outline: 0px; font-size: 1.25em; vertical-align: baseline; background-color: transparent; font-family: sans-serif; font-weight: bold; color: rgb(0, 0, 51); font-style: normal; font-variant: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
Exercise</h5>
<ul style="margin: 0.5em 1em 1em; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
	<li style="margin: 0.5em 0px 0px 1em; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; background-position: initial initial; background-repeat: initial initial;">
	Assume that the following<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">enum</code><span class="Apple-converted-space">&nbsp;</span>is
	already defined:<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); background-position: initial initial; background-repeat: initial initial;"><span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">enum</span> Operation { add, subtract, multiply, divide }
</pre>
	<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); background-position: initial initial; background-repeat: initial initial;">
	Also assume that there is a<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">struct</code><span class="Apple-converted-space">&nbsp;</span>that
	represents the calculation of an operation and its two operands:</p>
	<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); background-position: initial initial; background-repeat: initial initial;"><span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">struct</span> Calculation
{
    Operation op;
    <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">double</span> first;
    <span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">double</span> second;
}
</pre>
	<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); background-position: initial initial; background-repeat: initial initial;">
	For example, the object<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">Calculation(Operation.divide,
	7.7, 8.8)</code><span class="Apple-converted-space">&nbsp;</span>would represent
	the division of 7.7 by 8.8.</p>
	<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); background-position: initial initial; background-repeat: initial initial;">
	Design a function that receives an unspecified number of these<code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">struct</code><span class="Apple-converted-space">&nbsp;</span>objects,
	calculates the result of each<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">Calculation</code>,
	and then returns all of the results as a slice of type<span class="Apple-converted-space">&nbsp;</span><code class="d_inline" style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 1.2em; vertical-align: baseline; background-color: transparent; font-weight: bold; color: rgb(0, 34, 34); background-position: initial initial; background-repeat: initial initial;">double[]</code>.</p>
	<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); background-position: initial initial; background-repeat: initial initial;">
	For example, it should be possible to call the function as in the following
	code:</p>
	<pre class="d_code" style="margin: 0.5em 1em 0.75em 16px; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 1em; vertical-align: baseline; background-color: rgb(255, 255, 255); background-position: initial initial; background-repeat: initial initial;"><span style="margin: 0px; padding: 0px; border: 0px; outline: 0px; font-size: 13px; vertical-align: baseline; background-color: transparent; color: blue; background-position: initial initial; background-repeat: initial initial;">void</span> main()
{
    writeln(calculate(Calculation(Operation.add, 1.1, 2.2),
                      Calculation(Operation.subtract, 3.3, 4.4),
                      Calculation(Operation.multiply, 5.5, 6.6),
                      Calculation(Operation.divide, 7.7, 8.8)));
}
</pre>
	<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); background-position: initial initial; background-repeat: initial initial;">
	The output of the code should be similar to the following:</p>
	<pre class="shell" style="margin: 0.5em 1em 1em; padding: 0.5em; border: 1px dotted rgb(153, 204, 153); outline: 0px; font-size: 13px; vertical-align: baseline; background-color: rgb(224, 224, 224); font-weight: bold; background-position: initial initial; background-repeat: initial initial;">[3.3, -1.1, 36.3, 0.875]
</pre>
	</li>
</ul>
<p style="margin: 0.75em 1em 0.75em 16px; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; color: rgb(0, 0, 0); font-family: serif; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 19px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">
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... the solution</i></a></p>
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