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<title>Generate a random integer</title>
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<div class="refnamediv">
<h1 class="refname">rand</h1>
<p class="verinfo">(PHP 4, PHP 5, PHP 7)</p><p class="refpurpose"><span class="refname">rand</span> — <span class="dc-title">Generate a random integer</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.rand-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">int</span> <span class="methodname"><strong>rand</strong></span>
( <span class="methodparam">void</span>
)</div>
<div class="methodsynopsis dc-description">
<span class="type">int</span> <span class="methodname"><strong>rand</strong></span>
( <span class="methodparam"><span class="type">int</span> <code class="parameter">$min</code></span>
, <span class="methodparam"><span class="type">int</span> <code class="parameter">$max</code></span>
)</div>
<p class="simpara">
If called without the optional <code class="parameter">min</code>,
<code class="parameter">max</code> arguments <span class="function"><strong>rand()</strong></span>
returns a pseudo-random integer between 0 and
<span class="function"><a href="function.getrandmax.html" class="function">getrandmax()</a></span>. If you want a random number
between 5 and 15 (inclusive), for example, use <em>rand(5,
15)</em>.
</p>
<div class="caution"><strong class="caution">Caution</strong><p class="para">This function does not
generate cryptographically secure values, and should not be used for cryptographic purposes. If you need a
cryptographically secure value, consider using <span class="function"><a href="function.random-int.html" class="function">random_int()</a></span>, <span class="function"><a href="function.random-bytes.html" class="function">random_bytes()</a></span>, or
<span class="function"><a href="function.openssl-random-pseudo-bytes.html" class="function">openssl_random_pseudo_bytes()</a></span> instead.</p></div>
<blockquote class="note"><p><strong class="note">Note</strong>:
<span class="simpara">
On some platforms (such as Windows), <span class="function"><a href="function.getrandmax.html" class="function">getrandmax()</a></span>
is only 32767. If you require a range larger than 32767, specifying
<code class="parameter">min</code> and <code class="parameter">max</code> will allow
you to create a range larger than this, or consider using
<span class="function"><a href="function.mt-rand.html" class="function">mt_rand()</a></span> instead.
</span>
</p></blockquote>
<blockquote class="note"><p><strong class="note">Note</strong>: <span class="simpara">As of PHP 7.1.0, <span class="function"><strong>rand()</strong></span> uses the same
random number generator as <span class="function"><a href="function.mt-rand.html" class="function">mt_rand()</a></span>. To preserve
backwards compatibility <span class="function"><strong>rand()</strong></span> allows
<code class="parameter">max</code> to be smaller than <code class="parameter">min</code>
as opposed to returning <strong><code>FALSE</code></strong> as <span class="function"><a href="function.mt-rand.html" class="function">mt_rand()</a></span>.</span>
</p></blockquote>
</div>
<div class="refsect1 parameters" id="refsect1-function.rand-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<code class="parameter">min</code></dt>
<dd>
<p class="para">
The lowest value to return (default: 0)
</p>
</dd>
<dt>
<code class="parameter">max</code></dt>
<dd>
<p class="para">
The highest value to return (default: <span class="function"><a href="function.getrandmax.html" class="function">getrandmax()</a></span>)
</p>
</dd>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.rand-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
A pseudo random value between <code class="parameter">min</code>
(or 0) and <code class="parameter">max</code> (or <span class="function"><a href="function.getrandmax.html" class="function">getrandmax()</a></span>, inclusive).
</p>
</div>
<div class="refsect1 changelog" id="refsect1-function.rand-changelog">
<h3 class="title">Changelog</h3>
<p class="para">
<table class="doctable informaltable">
<thead>
<tr>
<th>Version</th>
<th>Description</th>
</tr>
</thead>
<tbody class="tbody">
<tr>
<td>7.2.0</td>
<td>
<span class="function"><strong>rand()</strong></span> <a href="migration72.incompatible.html#migration72.incompatible.rand-mt_rand-output" class="link">has received a bug fix</a> for a modulo bias bug. This means that sequences generated with a specific seed may differ from PHP 7.1 on 64-bit machines.
</td>
</tr>
<tr>
<td>7.1.0</td>
<td>
<span class="function"><strong>rand()</strong></span> <a href="migration71.incompatible.html#migration71.incompatible.rand-srand-aliases" class="link">has been made</a> an alias of <span class="function"><a href="function.mt-rand.html" class="function">mt_rand()</a></span>.
</td>
</tr>
</tbody>
</table>
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.rand-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-4269">
<p><strong>Example #1 <span class="function"><strong>rand()</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: #007700">echo </span><span style="color: #0000BB">rand</span><span style="color: #007700">() . </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo </span><span style="color: #0000BB">rand</span><span style="color: #007700">() . </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br /><br />echo </span><span style="color: #0000BB">rand</span><span style="color: #007700">(</span><span style="color: #0000BB">5</span><span style="color: #007700">, </span><span style="color: #0000BB">15</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
something similar to:</p></div>
<div class="example-contents screen">
<div class="cdata"><pre>
7771
22264
11
</pre></div>
</div>
</div>
</p>
</div>
<div class="refsect1 notes" id="refsect1-function.rand-notes">
<h3 class="title">Notes</h3>
<div class="warning"><strong class="warning">Warning</strong>
<p class="para">
<code class="parameter">min</code> <code class="parameter">max</code> range must
be within the range <span class="function"><a href="function.getrandmax.html" class="function">getrandmax()</a></span>. i.e. (<code class="parameter">max</code> -
<code class="parameter">min</code>) <= <span class="function"><a href="function.getrandmax.html" class="function">getrandmax()</a></span>
Otherwise, <span class="function"><strong>rand()</strong></span> may return poor-quality random numbers.
</p>
</div>
</div>
<div class="refsect1 seealso" id="refsect1-function.rand-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"><span class="function"><a href="function.srand.html" class="function" rel="rdfs-seeAlso">srand()</a> - Seed the random number generator</span></li>
<li class="member"><span class="function"><a href="function.getrandmax.html" class="function" rel="rdfs-seeAlso">getrandmax()</a> - Show largest possible random value</span></li>
<li class="member"><span class="function"><a href="function.mt-rand.html" class="function" rel="rdfs-seeAlso">mt_rand()</a> - Generate a random value via the Mersenne Twister Random Number Generator</span></li>
<li class="member"><span class="function"><a href="function.random-int.html" class="function" rel="rdfs-seeAlso">random_int()</a> - Generates cryptographically secure pseudo-random integers</span></li>
<li class="member"><span class="function"><a href="function.random-bytes.html" class="function" rel="rdfs-seeAlso">random_bytes()</a> - Generates cryptographically secure pseudo-random bytes</span></li>
<li class="member"><span class="function"><a href="function.openssl-random-pseudo-bytes.html" class="function" rel="rdfs-seeAlso">openssl_random_pseudo_bytes()</a> - Generate a pseudo-random string of bytes</span></li>
</ul>
</p>
</div>
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