<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="generator" content="rustdoc">
<title>Primitive Types</title>
<link rel="stylesheet" type="text/css" href="../rust.css">
<link rel="shortcut icon" href="https://www.rust-lang.org/favicon.ico">
</head>
<body class="rustdoc">
<!--[if lte IE 8]>
<div class="warning">
This old browser is unsupported and will most likely display funky
things.
</div>
<![endif]-->
<div id="versioninfo">
<img src="https://www.rust-lang.org/logos/rust-logo-32x32-blk.png" width="32" height="32" alt="Rust logo"><br>
<span class="white-sticker"><a href="https://www.rust-lang.org">Rust</a> 1.27.1</span><br>
<a href="https://github.com/rust-lang/rust/commit/"
class="hash white-sticker"></a>
</div>
<h1 class="title">Primitive Types</h1>
<p><small>There is a new edition of the book and this is an old link.</small></p>
<blockquote>
<p>Rust is a <em>statically typed</em> language, which means that it must know the types of all variables at compile time.
The compiler can usually infer what type we want to use based on the value and how we use it.
In cases when many types are possible, a <em>type annotation</em> must be added.</p>
</blockquote>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="number">2.0</span>; <span class="comment">// f64</span>
<span class="kw">let</span> <span class="ident">y</span>: <span class="ident">f32</span> <span class="op">=</span> <span class="number">3.0</span>; <span class="comment">// f32</span><a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=%23!%5Ballow(unused)%5D%0Afn%20main()%20%7B%0Alet%20x%20%3D%202.0%3B%20%2F%2F%20f64%0A%0Alet%20y%3A%20f32%20%3D%203.0%3B%20%2F%2F%20f32%0A%7D">Run</a></pre>
<hr />
<p>Here are the relevant sections in the new and old books:</p>
<ul>
<li><strong><a href="second-edition/ch03-02-data-types.html">In the second edition: Ch 3.02 — Data Types</a></strong></li>
<li><small><a href="first-edition/primitive-types.html">In the first edition: Ch 3.3 — Primitive Types</a></small></li>
</ul>
<footer><p>
Copyright © 2011 The Rust Project Developers. Licensed under the
<a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>
or the <a href="https://opensource.org/licenses/MIT">MIT license</a>, at your option.
</p><p>
This file may not be copied, modified, or distributed except according to those terms.
</p></footer>
</body>
</html>
