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<h1 class="title">`const` and `static`</h1>
<p><small>There is a new edition of the book and this is an old link.</small></p>
<blockquote>
<p>Constants are <em>always</em> immutable, and may only be set to a constant expression, not the result of a function call or any other value that could only be computed at runtime.</p>
<p>Global variables are called <code>static</code> in Rust.</p>
</blockquote>
<pre class="rust rust-example-rendered">
<span class="kw">const</span> <span class="ident">MAX_POINTS</span>: <span class="ident">u32</span> <span class="op">=</span> <span class="number">100_000</span>;
<span class="kw">static</span> <span class="ident">HELLO_WORLD</span>: <span class="kw-2">&</span><span class="ident">str</span> <span class="op">=</span> <span class="string">"Hello, world!"</span>;<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=%23!%5Ballow(unused)%5D%0Afn%20main()%20%7B%0Aconst%20MAX_POINTS%3A%20u32%20%3D%20100_000%3B%0Astatic%20HELLO_WORLD%3A%20%26str%20%3D%20%22Hello%2C%20world!%22%3B%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/ch03-01-variables-and-mutability.html#differences-between-variables-and-constants">In the second edition: Ch 3.01 — Variables and Mutability, section Constants</a></strong></li>
<li><strong><a href="second-edition/ch19-01-unsafe-rust.html#accessing-or-modifying-a-mutable-static-variable">In the second edition: Ch 19.01 — Unsafe Rust, section Static Variables</a></strong></li>
<li><small><a href="first-edition/const-and-static.html">In the first edition: Ch 3.26 — <code>const</code> and <code>static</code></a></small></li>
</ul>
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