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<title>Convert a number between arbitrary bases</title>
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<div class="refnamediv">
<h1 class="refname">base_convert</h1>
<p class="verinfo">(PHP 4, PHP 5, PHP 7)</p><p class="refpurpose"><span class="refname">base_convert</span> — <span class="dc-title">Convert a number between arbitrary bases</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.base-convert-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">string</span> <span class="methodname"><strong>base_convert</strong></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$number</code></span>
, <span class="methodparam"><span class="type">int</span> <code class="parameter">$frombase</code></span>
, <span class="methodparam"><span class="type">int</span> <code class="parameter">$tobase</code></span>
)</div>
<p class="para rdfs-comment">
Returns a string containing <code class="parameter">number</code>
represented in base <code class="parameter">tobase</code>. The base in
which <code class="parameter">number</code> is given is specified in
<code class="parameter">frombase</code>. Both
<code class="parameter">frombase</code> and <code class="parameter">tobase</code>
have to be between 2 and 36, inclusive. Digits in numbers with a
base higher than 10 will be represented with the letters a-z,
with a meaning 10, b meaning 11 and z meaning 35.
The case of the letters doesn't matter, i.e.
<code class="parameter">number</code> is interpreted case-insensitively.
</p>
<div class="warning"><strong class="warning">Warning</strong>
<p class="simpara">
<span class="function"><strong>base_convert()</strong></span> may lose precision on large numbers
due to properties related to the internal "double" or "float" type used.
Please see the <a href="language.types.float.html" class="link">Floating point numbers</a>
section in the manual for more specific information and limitations.
</p>
</div>
</div>
<div class="refsect1 parameters" id="refsect1-function.base-convert-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<code class="parameter">number</code></dt>
<dd>
<p class="para">
The number to convert. Any invalid characters in
<code class="parameter">number</code> are silently ignored.
</p>
</dd>
<dt>
<code class="parameter">frombase</code></dt>
<dd>
<p class="para">
The base <code class="parameter">number</code> is in
</p>
</dd>
<dt>
<code class="parameter">tobase</code></dt>
<dd>
<p class="para">
The base to convert <code class="parameter">number</code> to
</p>
</dd>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.base-convert-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
<code class="parameter">number</code> converted to base <code class="parameter">tobase</code>
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.base-convert-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-4244">
<p><strong>Example #1 <span class="function"><strong>base_convert()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$hexadecimal </span><span style="color: #007700">= </span><span style="color: #DD0000">'a37334'</span><span style="color: #007700">;<br />echo </span><span style="color: #0000BB">base_convert</span><span style="color: #007700">(</span><span style="color: #0000BB">$hexadecimal</span><span style="color: #007700">, </span><span style="color: #0000BB">16</span><span style="color: #007700">, </span><span style="color: #0000BB">2</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
<div class="example-contents"><p>The above example will output:</p></div>
<div class="example-contents screen">
<div class="cdata"><pre>
101000110111001100110100
</pre></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.base-convert-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"><span class="function"><a href="function.intval.html" class="function" rel="rdfs-seeAlso">intval()</a> - Get the integer value of a variable</span></li>
</ul>
</p>
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