189 lines
7.1 KiB
Plaintext
Generated
189 lines
7.1 KiB
Plaintext
Generated
<!DOCTYPE html>
|
|
<html>
|
|
<head>
|
|
<meta charset="utf-8">
|
|
<title>Go by Example: If/Else</title>
|
|
<link rel=stylesheet href="site.css">
|
|
</head>
|
|
<script>
|
|
onkeydown = (e) => {
|
|
|
|
if (e.key == "ArrowLeft") {
|
|
window.location.href = 'for';
|
|
}
|
|
|
|
|
|
if (e.key == "ArrowRight") {
|
|
window.location.href = 'switch';
|
|
}
|
|
|
|
}
|
|
</script>
|
|
<body>
|
|
<div class="example" id="if-else">
|
|
<h2><a href="./">Go by Example</a>: If/Else</h2>
|
|
|
|
<table>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>Branching with <code>if</code> and <code>else</code> in Go is
|
|
straight-forward.</p>
|
|
|
|
</td>
|
|
<td class="code empty leading">
|
|
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
<a href="http://play.golang.org/p/QlMkcwHvmns"><img title="Run code" src="play.png" class="run" /></a><img title="Copy code" src="clipboard.png" class="copy" />
|
|
<pre class="chroma"><span class="kn">package</span> <span class="nx">main</span>
|
|
</pre>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<pre class="chroma"><span class="kn">import</span> <span class="s">"fmt"</span>
|
|
</pre>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<pre class="chroma"><span class="kd">func</span> <span class="nf">main</span><span class="p">()</span> <span class="p">{</span>
|
|
</pre>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>Here’s a basic example.</p>
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<pre class="chroma">
|
|
<span class="k">if</span> <span class="mi">7</span><span class="o">%</span><span class="mi">2</span> <span class="o">==</span> <span class="mi">0</span> <span class="p">{</span>
|
|
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="s">"7 is even"</span><span class="p">)</span>
|
|
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
|
|
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="s">"7 is odd"</span><span class="p">)</span>
|
|
<span class="p">}</span>
|
|
</pre>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>You can have an <code>if</code> statement without an else.</p>
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<pre class="chroma">
|
|
<span class="k">if</span> <span class="mi">8</span><span class="o">%</span><span class="mi">4</span> <span class="o">==</span> <span class="mi">0</span> <span class="p">{</span>
|
|
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="s">"8 is divisible by 4"</span><span class="p">)</span>
|
|
<span class="p">}</span>
|
|
</pre>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>A statement can precede conditionals; any variables
|
|
declared in this statement are available in all
|
|
branches.</p>
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<pre class="chroma">
|
|
<span class="k">if</span> <span class="nx">num</span> <span class="o">:=</span> <span class="mi">9</span><span class="p">;</span> <span class="nx">num</span> <span class="p"><</span> <span class="mi">0</span> <span class="p">{</span>
|
|
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nx">num</span><span class="p">,</span> <span class="s">"is negative"</span><span class="p">)</span>
|
|
<span class="p">}</span> <span class="k">else</span> <span class="k">if</span> <span class="nx">num</span> <span class="p"><</span> <span class="mi">10</span> <span class="p">{</span>
|
|
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nx">num</span><span class="p">,</span> <span class="s">"has 1 digit"</span><span class="p">)</span>
|
|
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
|
|
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nx">num</span><span class="p">,</span> <span class="s">"has multiple digits"</span><span class="p">)</span>
|
|
<span class="p">}</span>
|
|
<span class="p">}</span>
|
|
</pre>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>Note that you don’t need parentheses around conditions
|
|
in Go, but that the braces are required.</p>
|
|
|
|
</td>
|
|
<td class="code empty">
|
|
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
</table>
|
|
|
|
<table>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<pre class="chroma"><span class="gp">$</span> go run if-else.go
|
|
<span class="go">7 is odd
|
|
</span><span class="go">8 is divisible by 4
|
|
</span><span class="go">9 has 1 digit</span></pre>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>There is no <a href="http://en.wikipedia.org/wiki/%3F:">ternary if</a>
|
|
in Go, so you’ll need to use a full <code>if</code> statement even
|
|
for basic conditions.</p>
|
|
|
|
</td>
|
|
<td class="code empty">
|
|
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
</table>
|
|
|
|
|
|
<p class="next">
|
|
Next example: <a href="switch">Switch</a>.
|
|
</p>
|
|
|
|
|
|
<p class="footer">
|
|
by <a href="https://markmcgranaghan.com">Mark McGranaghan</a> and <a href="https://eli.thegreenplace.net">Eli Bendersky</a> | <a href="https://github.com/mmcgrana/gobyexample">source</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a>
|
|
</p>
|
|
|
|
</div>
|
|
<script>
|
|
var codeLines = [];
|
|
codeLines.push('');codeLines.push('package main\u000A');codeLines.push('import \"fmt\"\u000A');codeLines.push('func main() {\u000A');codeLines.push(' if 7%2 \u003D\u003D 0 {\u000A fmt.Println(\"7 is even\")\u000A } else {\u000A fmt.Println(\"7 is odd\")\u000A }\u000A');codeLines.push(' if 8%4 \u003D\u003D 0 {\u000A fmt.Println(\"8 is divisible by 4\")\u000A }\u000A');codeLines.push(' if num :\u003D 9; num \u003C 0 {\u000A fmt.Println(num, \"is negative\")\u000A } else if num \u003C 10 {\u000A fmt.Println(num, \"has 1 digit\")\u000A } else {\u000A fmt.Println(num, \"has multiple digits\")\u000A }\u000A}\u000A');codeLines.push('');codeLines.push('');codeLines.push('');
|
|
</script>
|
|
<script src="site.js" async></script>
|
|
</body>
|
|
</html>
|