gobyexample/public/multiple-return-values
Eli Bendersky baf22e84e7 Move <img> for play.golang.org to separate line in the template
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Note that there are whitespace diffs in the generated files where there
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Fixes #235
2019-06-04 19:03:37 -07:00

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<title>Go by Example: Multiple Return Values</title>
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<div class="example" id="multiple-return-values">
<h2><a href="./">Go by Example</a>: Multiple Return Values</h2>
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<p>Go has built-in support for <em>multiple return values</em>.
This feature is used often in idiomatic Go, for example
to return both result and error values from a function.</p>
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<a href="http://play.golang.org/p/FZoIB5LXQGZ">
<img title="Run code" class="run" src="data:image/png;base64,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" />
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<div class="highlight"><pre><span class="kn">package</span> <span class="nx">main</span>
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<div class="highlight"><pre><span class="kn">import</span> <span class="s">&quot;fmt&quot;</span>
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<p>The <code>(int, int)</code> in this function signature shows that
the function returns 2 <code>int</code>s.</p>
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<div class="highlight"><pre><span class="kd">func</span> <span class="nx">vals</span><span class="p">()</span> <span class="p">(</span><span class="kt">int</span><span class="p">,</span> <span class="kt">int</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="mi">3</span><span class="p">,</span> <span class="mi">7</span>
<span class="p">}</span>
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<div class="highlight"><pre><span class="kd">func</span> <span class="nx">main</span><span class="p">()</span> <span class="p">{</span>
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<p>Here we use the 2 different return values from the
call with <em>multiple assignment</em>.</p>
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<div class="highlight"><pre> <span class="nx">a</span><span class="p">,</span> <span class="nx">b</span> <span class="o">:=</span> <span class="nx">vals</span><span class="p">()</span>
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="nx">a</span><span class="p">)</span>
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="nx">b</span><span class="p">)</span>
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<p>If you only want a subset of the returned values,
use the blank identifier <code>_</code>.</p>
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<div class="highlight"><pre> <span class="nx">_</span><span class="p">,</span> <span class="nx">c</span> <span class="o">:=</span> <span class="nx">vals</span><span class="p">()</span>
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="nx">c</span><span class="p">)</span>
<span class="p">}</span>
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<div class="highlight"><pre><span class="gp">$</span> go run multiple-return-values.go
<span class="go">3</span>
<span class="go">7</span>
<span class="go">7</span>
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<p>Accepting a variable number of arguments is another nice
feature of Go functions; we&rsquo;ll look at this next.</p>
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<p class="next">
Next example: <a href="variadic-functions">Variadic Functions</a>.
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<p class="footer">
by <a href="https://markmcgranaghan.com">Mark McGranaghan</a> | <a href="https://github.com/mmcgrana/gobyexample/blob/master/examples/multiple-return-values">source</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a>
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