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<h1 class='fqn'><span class='in-band'>Function <a href='../index.html'>std_unicode</a>::<wbr><a href='index.html'>char</a>::<wbr><a class="fn" href=''>from_digit</a></span><span class='out-of-band'><span class='since' title='Stable since Rust version 1.0.0'>1.0.0</span><span id='render-detail'>
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</span><a class='srclink' href='../../src/core/char.rs.html#293-307' title='goto source code'>[src]</a></span></h1>
<pre class='rust fn'>pub fn from_digit(num: u32, radix: u32) -> <a class="enum" href="../../core/option/enum.Option.html" title="enum core::option::Option">Option</a><char></pre><div class='docblock'><p>Converts a digit in the given radix to a <code>char</code>.</p>
<p>A 'radix' here is sometimes also called a 'base'. A radix of two
indicates a binary number, a radix of ten, decimal, and a radix of
sixteen, hexadecimal, to give some common values. Arbitrary
radices are supported.</p>
<p><code>from_digit()</code> will return <code>None</code> if the input is not a digit in
the given radix.</p>
<h1 id='panics' class='section-header'><a href='#panics'>Panics</a></h1>
<p>Panics if given a radix larger than 36.</p>
<h1 id='examples' class='section-header'><a href='#examples'>Examples</a></h1>
<p>Basic usage:</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">char</span>;
<span class="kw">let</span> <span class="ident">c</span> <span class="op">=</span> <span class="ident">char</span>::<span class="ident">from_digit</span>(<span class="number">4</span>, <span class="number">10</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">Some</span>(<span class="string">'4'</span>), <span class="ident">c</span>);
<span class="comment">// Decimal 11 is a single digit in base 16</span>
<span class="kw">let</span> <span class="ident">c</span> <span class="op">=</span> <span class="ident">char</span>::<span class="ident">from_digit</span>(<span class="number">11</span>, <span class="number">16</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">Some</span>(<span class="string">'b'</span>), <span class="ident">c</span>);<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=fn%20main()%20%7B%0Ause%20std%3A%3Achar%3B%0A%0Alet%20c%20%3D%20char%3A%3Afrom_digit(4%2C%2010)%3B%0A%0Aassert_eq!(Some('4')%2C%20c)%3B%0A%0A%2F%2F%20Decimal%2011%20is%20a%20single%20digit%20in%20base%2016%0Alet%20c%20%3D%20char%3A%3Afrom_digit(11%2C%2016)%3B%0A%0Aassert_eq!(Some('b')%2C%20c)%3B%0A%7D">Run</a></pre>
<p>Returning <code>None</code> when the input is not a digit:</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">char</span>;
<span class="kw">let</span> <span class="ident">c</span> <span class="op">=</span> <span class="ident">char</span>::<span class="ident">from_digit</span>(<span class="number">20</span>, <span class="number">10</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">None</span>, <span class="ident">c</span>);<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=fn%20main()%20%7B%0Ause%20std%3A%3Achar%3B%0A%0Alet%20c%20%3D%20char%3A%3Afrom_digit(20%2C%2010)%3B%0A%0Aassert_eq!(None%2C%20c)%3B%0A%7D">Run</a></pre>
<p>Passing a large radix, causing a panic:</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">thread</span>;
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">char</span>;
<span class="kw">let</span> <span class="ident">result</span> <span class="op">=</span> <span class="ident">thread</span>::<span class="ident">spawn</span>(<span class="op">||</span> {
<span class="comment">// this panics</span>
<span class="kw">let</span> <span class="ident">c</span> <span class="op">=</span> <span class="ident">char</span>::<span class="ident">from_digit</span>(<span class="number">1</span>, <span class="number">37</span>);
}).<span class="ident">join</span>();
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">result</span>.<span class="ident">is_err</span>());<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=fn%20main()%20%7B%0Ause%20std%3A%3Athread%3B%0Ause%20std%3A%3Achar%3B%0A%0Alet%20result%20%3D%20thread%3A%3Aspawn(%7C%7C%20%7B%0A%20%20%20%20%2F%2F%20this%20panics%0A%20%20%20%20let%20c%20%3D%20char%3A%3Afrom_digit(1%2C%2037)%3B%0A%7D).join()%3B%0A%0Aassert!(result.is_err())%3B%0A%7D">Run</a></pre>
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