197 lines
8.1 KiB
Plaintext
Generated
197 lines
8.1 KiB
Plaintext
Generated
<!DOCTYPE html>
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<html>
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<head>
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<meta charset="utf-8">
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<title>Go by Example: Functions</title>
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<link rel=stylesheet href="site.css">
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</head>
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window.location.href = 'multiple-return-values';
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<body>
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<div class="example" id="functions">
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<h2><a href="./">Go by Example</a>: Functions</h2>
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<table>
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<tr>
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<td class="docs">
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<p><em>Functions</em> are central in Go. We’ll learn about
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functions with a few different examples.</p>
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</td>
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<td class="code empty leading">
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code leading">
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<a href="https://go.dev/play/p/-o49-dQfGbK"><img title="Run code" src="play.png" class="run" /></a><img title="Copy code" src="clipboard.png" class="copy" />
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<pre class="chroma"><code><span class="line"><span class="cl"><span class="kn">package</span> <span class="nx">main</span></span></span></code></pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code leading">
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<pre class="chroma"><code><span class="line"><span class="cl"><span class="kn">import</span> <span class="s">"fmt"</span></span></span></code></pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>Here’s a function that takes two <code>int</code>s and returns
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their sum as an <code>int</code>.</p>
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</td>
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<td class="code leading">
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<pre class="chroma"><code><span class="line"><span class="cl"><span class="kd">func</span> <span class="nf">plus</span><span class="p">(</span><span class="nx">a</span> <span class="kt">int</span><span class="p">,</span> <span class="nx">b</span> <span class="kt">int</span><span class="p">)</span> <span class="kt">int</span> <span class="p">{</span></span></span></code></pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>Go requires explicit returns, i.e. it won’t
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automatically return the value of the last
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expression.</p>
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</td>
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<td class="code leading">
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<pre class="chroma"><code><span class="line"><span class="cl"> <span class="k">return</span> <span class="nx">a</span> <span class="o">+</span> <span class="nx">b</span>
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</span></span><span class="line"><span class="cl"><span class="p">}</span></span></span></code></pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>When you have multiple consecutive parameters of
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the same type, you may omit the type name for the
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like-typed parameters up to the final parameter that
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declares the type.</p>
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</td>
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<td class="code leading">
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<pre class="chroma"><code><span class="line"><span class="cl"><span class="kd">func</span> <span class="nf">plusPlus</span><span class="p">(</span><span class="nx">a</span><span class="p">,</span> <span class="nx">b</span><span class="p">,</span> <span class="nx">c</span> <span class="kt">int</span><span class="p">)</span> <span class="kt">int</span> <span class="p">{</span>
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</span></span><span class="line"><span class="cl"> <span class="k">return</span> <span class="nx">a</span> <span class="o">+</span> <span class="nx">b</span> <span class="o">+</span> <span class="nx">c</span>
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</span></span><span class="line"><span class="cl"><span class="p">}</span></span></span></code></pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code leading">
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<pre class="chroma"><code><span class="line"><span class="cl"><span class="kd">func</span> <span class="nf">main</span><span class="p">()</span> <span class="p">{</span></span></span></code></pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>Call a function just as you’d expect, with
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<code>name(args)</code>.</p>
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</td>
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<td class="code leading">
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<pre class="chroma"><code><span class="line"><span class="cl"> <span class="nx">res</span> <span class="o">:=</span> <span class="nf">plus</span><span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">)</span>
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</span></span><span class="line"><span class="cl"> <span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="s">"1+2 ="</span><span class="p">,</span> <span class="nx">res</span><span class="p">)</span></span></span></code></pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code">
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<pre class="chroma"><code><span class="line"><span class="cl"> <span class="nx">res</span> <span class="p">=</span> <span class="nf">plusPlus</span><span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">,</span> <span class="mi">3</span><span class="p">)</span>
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</span></span><span class="line"><span class="cl"> <span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="s">"1+2+3 ="</span><span class="p">,</span> <span class="nx">res</span><span class="p">)</span>
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</span></span><span class="line"><span class="cl"><span class="p">}</span></span></span></code></pre>
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</td>
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</tr>
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</table>
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<table>
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<tr>
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<td class="docs">
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</td>
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<td class="code leading">
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<pre class="chroma"><code><span class="line"><span class="cl"><span class="gp">$</span> go run functions.go
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</span></span><span class="line"><span class="cl"><span class="go">1+2 = 3
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</span></span></span><span class="line"><span class="cl"><span class="go">1+2+3 = 6</span></span></span></code></pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>There are several other features to Go functions. One is
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multiple return values, which we’ll look at next.</p>
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</td>
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<td class="code empty">
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</td>
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</tr>
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</table>
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<p class="next">
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Next example: <a href="multiple-return-values" rel="next">Multiple Return Values</a>.
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</p>
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<p class="footer">
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Based on
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<em><a href="https://gobyexample.com/">Go by Example</a></em>
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by <a href="https://markmcgranaghan.com">Mark McGranaghan</a>
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and <a href="https://eli.thegreenplace.net">Eli Bendersky</a>,
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licensed under
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<a href="https://creativecommons.org/licenses/by/3.0/">CC BY 3.0</a>.
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<a href="https://git.inkch.xyz/inkch/gobyexample/commit/de3b5db09c9b980ba971c708a3fe522606e44572">
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Style modifications by inkch
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</a>.
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<a href="https://github.com/mmcgrana/gobyexample">Original source</a>.
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</p>
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</div>
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<script>
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var codeLines = [];
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codeLines.push('');codeLines.push('package main\u000A');codeLines.push('import \"fmt\"\u000A');codeLines.push('func plus(a int, b int) int {\u000A');codeLines.push(' return a + b\u000A}\u000A');codeLines.push('func plusPlus(a, b, c int) int {\u000A return a + b + c\u000A}\u000A');codeLines.push('func main() {\u000A');codeLines.push(' res :\u003D plus(1, 2)\u000A fmt.Println(\"1+2 \u003D\", res)\u000A');codeLines.push(' res \u003D plusPlus(1, 2, 3)\u000A fmt.Println(\"1+2+3 \u003D\", res)\u000A}\u000A');codeLines.push('');codeLines.push('');
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