<!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>Sets the RNG seed</title>
</head>
<body><div class="manualnavbar" style="text-align: center;">
<div class="prev" style="text-align: left; float: left;"><a href="function.gmp-random-range.html">gmp_random_range</a></div>
<div class="next" style="text-align: right; float: right;"><a href="function.gmp-random.html">gmp_random</a></div>
<div class="up"><a href="ref.gmp.html">GMP Functions</a></div>
<div class="home"><a href="index.html">PHP Manual</a></div>
</div><hr /><div id="function.gmp-random-seed" class="refentry">
<div class="refnamediv">
<h1 class="refname">gmp_random_seed</h1>
<p class="verinfo">(PHP 7)</p><p class="refpurpose"><span class="refname">gmp_random_seed</span> — <span class="dc-title">Sets the RNG seed</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.gmp-random-seed-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type"><span class="type void">void</span></span> <span class="methodname"><strong>gmp_random_seed</strong></span>
( <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$seed</code></span>
)</div>
</div>
<div class="refsect1 parameters" id="refsect1-function.gmp-random-seed-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<code class="parameter">seed</code></dt>
<dd>
<p class="para">
The seed to be set for the <span class="function"><a href="function.gmp-random.html" class="function">gmp_random()</a></span>,
<span class="function"><a href="function.gmp-random-bits.html" class="function">gmp_random_bits()</a></span>, and
<span class="function"><a href="function.gmp-random-range.html" class="function">gmp_random_range()</a></span> functions.
</p>
<p class="para">Either a GMP number <span class="type"><a href="language.types.resource.html" class="type resource">resource</a></span> in PHP 5.5 and earlier, a <a href="class.gmp.html" class="classname">GMP</a> object in PHP 5.6 and later, or a numeric string provided that it is possible to convert the latter to a number.</p>
</dd>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.gmp-random-seed-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns <strong><code>NULL</code></strong> on success or <strong><code>FALSE</code></strong> on failure.
</p>
</div>
<div class="refsect1 errors" id="refsect1-function.gmp-random-seed-errors">
<h3 class="title">Errors/Exceptions</h3>
<p class="para">
Issues an <strong><code>E_WARNING</code></strong> and returns <strong><code>FALSE</code></strong> if
<code class="parameter">seed</code> is not valid.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.gmp-random-seed-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-4223">
<p><strong>Example #1 <span class="function"><strong>gmp_random_seed()</strong></span> 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: #FF8000">// set the seed<br /></span><span style="color: #0000BB">gmp_random_seed</span><span style="color: #007700">(</span><span style="color: #0000BB">100</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">gmp_strval</span><span style="color: #007700">(</span><span style="color: #0000BB">gmp_random</span><span style="color: #007700">(</span><span style="color: #0000BB">1</span><span style="color: #007700">)));<br /><br /></span><span style="color: #FF8000">// set the seed to something else<br /></span><span style="color: #0000BB">gmp_random_seed</span><span style="color: #007700">(</span><span style="color: #0000BB">gmp_init</span><span style="color: #007700">(-</span><span style="color: #0000BB">100</span><span style="color: #007700">));<br /><br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">gmp_strval</span><span style="color: #007700">(</span><span style="color: #0000BB">gmp_random_bits</span><span style="color: #007700">(</span><span style="color: #0000BB">10</span><span style="color: #007700">)));<br /><br /></span><span style="color: #FF8000">// set the seed to something invalid<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">gmp_random_seed</span><span style="color: #007700">(</span><span style="color: #DD0000">'not a number'</span><span style="color: #007700">));</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>
string(20) "15370156633245019617"
string(3) "683"
Warning: gmp_random_seed(): Unable to convert variable to GMP - string is not an integer in %s on line %d
bool(false)
</pre></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.gmp-random-seed-seealso">
<h3 class="title">See Also</h3>
<ul class="simplelist">
<li class="member"><span class="function"><a href="function.gmp-init.html" class="function" rel="rdfs-seeAlso">gmp_init()</a> - Create GMP number</span></li>
<li class="member"><span class="function"><a href="function.gmp-random.html" class="function" rel="rdfs-seeAlso">gmp_random()</a> - Random number</span></li>
<li class="member"><span class="function"><a href="function.gmp-random-bits.html" class="function" rel="rdfs-seeAlso">gmp_random_bits()</a> - Random number</span></li>
<li class="member"><span class="function"><a href="function.gmp-random-range.html" class="function" rel="rdfs-seeAlso">gmp_random_range()</a> - Random number</span></li>
</ul>
</div>
</div><hr /><div class="manualnavbar" style="text-align: center;">
<div class="prev" style="text-align: left; float: left;"><a href="function.gmp-random-range.html">gmp_random_range</a></div>
<div class="next" style="text-align: right; float: right;"><a href="function.gmp-random.html">gmp_random</a></div>
<div class="up"><a href="ref.gmp.html">GMP Functions</a></div>
<div class="home"><a href="index.html">PHP Manual</a></div>
</div></body></html>
