<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Raise an arbitrary precision number to another</title> </head> <body><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.bcmul.html">bcmul</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.bcpowmod.html">bcpowmod</a></div> <div class="up"><a href="ref.bc.html">BC Math Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div><hr /><div id="function.bcpow" class="refentry"> <div class="refnamediv"> <h1 class="refname">bcpow</h1> <p class="verinfo">(PHP 4, PHP 5, PHP 7)</p><p class="refpurpose"><span class="refname">bcpow</span> — <span class="dc-title">Raise an arbitrary precision number to another</span></p> </div> <div class="refsect1 description" id="refsect1-function.bcpow-description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">string</span> <span class="methodname"><strong>bcpow</strong></span> ( <span class="methodparam"><span class="type">string</span> <code class="parameter">$base</code></span> , <span class="methodparam"><span class="type">string</span> <code class="parameter">$exponent</code></span> [, <span class="methodparam"><span class="type">int</span> <code class="parameter">$scale</code><span class="initializer"> = 0</span></span> ] )</div> <p class="para rdfs-comment"> Raise <code class="parameter">base</code> to the power <code class="parameter">exponent</code>. </p> </div> <div class="refsect1 parameters" id="refsect1-function.bcpow-parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt> <code class="parameter">base</code></dt> <dd> <p class="para"> The base, as a string. </p> </dd> <dt> <code class="parameter">exponent</code></dt> <dd> <p class="para"> The exponent, as a string. If the exponent is non-integral, it is truncated. The valid range of the exponent is platform specific, but is at least <em>-2147483648</em> to <em>2147483647</em>. </p> </dd> <dt> <code class="parameter"> scale</code></dt> <dd> <p class="para">This optional parameter is used to set the number of digits after the decimal place in the result. If omitted, it will default to the scale set globally with the <span class="function"><a href="function.bcscale.html" class="function">bcscale()</a></span> function, or fallback to <em>0</em> if this has not been set.</p></dd> </dl> </p> </div> <div class="refsect1 returnvalues" id="refsect1-function.bcpow-returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns the result as a string. </p> </div> <div class="refsect1 changelog" id="refsect1-function.bcpow-changelog"> <h3 class="title">Changelog</h3> <table class="doctable informaltable"> <thead> <tr> <th>Version</th> <th>Description</th> </tr> </thead> <tbody class="tbody"> <tr> <td>7.3.0</td> <td> <span class="function"><strong>bcpow()</strong></span> now returns numbers with the requested scale. Formerly, the returned numbers may have omitted trailing decimal zeroes. </td> </tr> </tbody> </table> </div> <div class="refsect1 examples" id="refsect1-function.bcpow-examples"> <h3 class="title">Examples</h3> <div class="example" id="example-4184"> <p><strong>Example #1 <span class="function"><strong>bcpow()</strong></span> example</strong></p> <div class="example-contents"> <div class="phpcode"><code><span style="color: #000000"> <span style="color: #0000BB"><?php<br /><br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">bcpow</span><span style="color: #007700">(</span><span style="color: #DD0000">'4.2'</span><span style="color: #007700">, </span><span style="color: #DD0000">'3'</span><span style="color: #007700">, </span><span style="color: #0000BB">2</span><span style="color: #007700">); </span><span style="color: #FF8000">// 74.08<br /><br /></span><span style="color: #0000BB">?></span> </span> </code></div> </div> </div> </div> <div class="refsect1 notes" id="refsect1-function.bcpow-notes"> <h3 class="title">Notes</h3> <blockquote class="note"><p><strong class="note">Note</strong>: <p class="para"> Before PHP 7.3.0 <span class="function"><strong>bcpow()</strong></span> may return a result with fewer digits after the decimal point than the <code class="parameter">scale</code> parameter would indicate. This only occurs when the result doesn't require all of the precision allowed by the <code class="parameter">scale</code>. For example: <div class="example" id="example-4185"> <p><strong>Example #2 <span class="function"><strong>bcpow()</strong></span> scale example</strong></p> <div class="example-contents"> <div class="phpcode"><code><span style="color: #000000"> <span style="color: #0000BB"><?php<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">bcpow</span><span style="color: #007700">(</span><span style="color: #DD0000">'5'</span><span style="color: #007700">, </span><span style="color: #DD0000">'2'</span><span style="color: #007700">, </span><span style="color: #0000BB">2</span><span style="color: #007700">); </span><span style="color: #FF8000">// prints "25", not "25.00"<br /></span><span style="color: #0000BB">?></span> </span> </code></div> </div> </div> </p> </p></blockquote> </div> <div class="refsect1 seealso" id="refsect1-function.bcpow-seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"><span class="function"><a href="function.bcpowmod.html" class="function" rel="rdfs-seeAlso">bcpowmod()</a> - Raise an arbitrary precision number to another, reduced by a specified modulus</span></li> <li class="member"><span class="function"><a href="function.bcsqrt.html" class="function" rel="rdfs-seeAlso">bcsqrt()</a> - Get the square root of an arbitrary precision number</span></li> </ul> </p> </div> </div><hr /><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.bcmul.html">bcmul</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.bcpowmod.html">bcpowmod</a></div> <div class="up"><a href="ref.bc.html">BC Math Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div></body></html>