PHP: random_int

<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml" lang="en"> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>PHP: random_int - Manual </title> <link rel="icon" type="image/svg+xml" sizes="any" href="https://www.php.net/favicon.svg?v=2"> <link rel="icon" type="image/png" sizes="196x196" href="https://www.php.net/favicon-196x196.png?v=2"> <link rel="icon" type="image/png" sizes="32x32" href="https://www.php.net/favicon-32x32.png?v=2"> <link rel="icon" type="image/png" sizes="16x16" href="https://www.php.net/favicon-16x16.png?v=2"> <link rel="shortcut icon" href="https://www.php.net/favicon.ico?v=2"> <link rel="search" type="application/opensearchdescription+xml" href="http://php.net/phpnetimprovedsearch.src" title="Add PHP.net search"> <link rel="alternate" type="application/atom+xml" href="https://www.php.net/releases/feed.php" title="PHP Release feed"> <link rel="alternate" type="application/atom+xml" href="https://www.php.net/feed.atom" title="PHP: Hypertext Preprocessor"> <link rel="canonical" href="https://www.php.net/manual/en/function.random-int.php"> <link rel="shorturl" href="https://www.php.net/random-int"> <link rel="alternate" href="https://www.php.net/random-int" hreflang="x-default"> <link rel="contents" href="https://www.php.net/manual/en/index.php"> <link rel="index" href="https://www.php.net/manual/en/ref.random.php"> <link rel="prev" href="https://www.php.net/manual/en/function.random-bytes.php"> <link rel="next" href="https://www.php.net/manual/en/function.srand.php"> <link rel="alternate" href="https://www.php.net/manual/en/function.random-int.php" hreflang="en"> <link rel="alternate" href="https://www.php.net/manual/de/function.random-int.php" hreflang="de"> <link rel="alternate" href="https://www.php.net/manual/es/function.random-int.php" hreflang="es"> <link rel="alternate" href="https://www.php.net/manual/fr/function.random-int.php" hreflang="fr"> <link rel="alternate" href="https://www.php.net/manual/it/function.random-int.php" hreflang="it"> <link rel="alternate" href="https://www.php.net/manual/ja/function.random-int.php" hreflang="ja"> <link rel="alternate" href="https://www.php.net/manual/pt_BR/function.random-int.php" hreflang="pt_BR"> <link rel="alternate" href="https://www.php.net/manual/ru/function.random-int.php" hreflang="ru"> <link rel="alternate" href="https://www.php.net/manual/tr/function.random-int.php" hreflang="tr"> <link rel="alternate" href="https://www.php.net/manual/uk/function.random-int.php" hreflang="uk"> <link rel="alternate" href="https://www.php.net/manual/zh/function.random-int.php" hreflang="zh"> <link rel="stylesheet" type="text/css" href="/cached.php?t=1707321815&f=/fonts/Fira/fira.css" media="screen"> <link rel="stylesheet" type="text/css" href="/cached.php?t=1707321815&f=/fonts/Font-Awesome/css/fontello.css" media="screen"> <link rel="stylesheet" type="text/css" href="/cached.php?t=1732428602&f=/styles/theme-base.css" media="screen"> <link rel="stylesheet" type="text/css" href="/cached.php?t=1730558402&f=/styles/theme-medium.css" media="screen"> <base href="https://www.php.net/manual/en/function.random-int.php"> <meta name="Description" content="PHP is a popular general-purpose scripting language that powers everything from your blog to the most popular websites in the world." /> <meta name="twitter:card" content="summary_large_image" /> <meta name="twitter:site" content="@official_php" /> <meta name="twitter:title" content="PHP: Hypertext Preprocessor" /> <meta name="twitter:description" content="PHP is a popular general-purpose scripting language that powers everything from your blog to the most popular websites in the world." /> <meta name="twitter:creator" content="@official_php" /> <meta name="twitter:image:src" content="https://www.php.net/images/meta-image.png" /> <meta itemprop="name" content="PHP: Hypertext Preprocessor" /> <meta itemprop="description" content="PHP is a popular general-purpose scripting language that powers everything from your blog to the most popular websites in the world." /> <meta itemprop="image" content="https://www.php.net/images/meta-image.png" /> <meta property="og:image" content="https://www.php.net/images/meta-image.png" /> <meta property="og:description" content="PHP is a popular general-purpose scripting language that powers everything from your blog to the most popular websites in the world." /> <link href="https://fosstodon.org/@php" rel="me" /> </head> <body class="docs "> <nav class="navbar navbar-fixed-top"> <div class="navbar__inner"> <a href="/" aria-label="PHP Home" class="navbar__brand"> <img src="/images/logos/php-logo-white.svg" aria-hidden="true" width="80" height="40" > </a> <div id="navbar__offcanvas" tabindex="-1" class="navbar__offcanvas" aria-label="Menu" > <button id="navbar__close-button" class="navbar__icon-item navbar_icon-item--visually-aligned navbar__close-button" > <svg xmlns="http://www.w3.org/2000/svg" width="24" viewBox="0 0 24 24" fill="currentColor"><path d="M19,6.41L17.59,5L12,10.59L6.41,5L5,6.41L10.59,12L5,17.59L6.41,19L12,13.41L17.59,19L19,17.59L13.41,12L19,6.41Z" /></svg> </button> <ul class="navbar__nav"> <li class="navbar__item"> <a href="/downloads.php" class="navbar__link " > Downloads </a> </li> <li class="navbar__item"> <a href="/docs.php" aria-current="page" class="navbar__link navbar__link--active " > Documentation </a> </li> <li class="navbar__item"> <a href="/get-involved.php" class="navbar__link " > Get Involved </a> </li> <li class="navbar__item"> <a href="/support.php" class="navbar__link " > Help </a> </li> <li class="navbar__item"> <a href="/releases/8.4/index.php" class="navbar__link navbar__release" > <img src="/images/php8/logo_php8_4.svg" alt="PHP 8.4"> </a> </li> </ul> </div> <div class="navbar__right">  <form action="/manual-lookup.php" class="navbar__search-form" > <label for="navbar__search-input" aria-label="Search docs"> <svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" width="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" > <circle cx="11" cy="11" r="8"></circle> <line x1="21" y1="21" x2="16.65" y2="16.65"></line> </svg> </label> <input type="search" name="pattern" id="navbar__search-input" class="navbar__search-input" placeholder="Search docs" accesskey="s" > <input type="hidden" name="scope" value="quickref"> </form>  <button id="navbar__search-button" class="navbar__search-button" hidden > <svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" width="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" > <circle cx="11" cy="11" r="8"></circle> <line x1="21" y1="21" x2="16.65" y2="16.65"></line> </svg> Search docs </button>  <a id="navbar__search-link" href="/lookup-form.php" aria-label="Search docs" class="navbar__icon-item navbar__search-link" > <svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" width="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" > <circle cx="11" cy="11" r="8"></circle> <line x1="21" y1="21" x2="16.65" y2="16.65"></line> </svg> </a> <a id="navbar__menu-link" href="/menu.php" aria-label="Menu" class="navbar__icon-item navbar_icon-item--visually-aligned navbar_menu-link" > <svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" width="24" viewBox="0 0 24 24" fill="currentColor" > <path d="M3,6H21V8H3V6M3,11H21V13H3V11M3,16H21V18H3V16Z" /> </svg> </a>  <button id="navbar__search-button-mobile" aria-label="Search docs" class="navbar__icon-item navbar__search-button-mobile" hidden > <svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" width="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" > <circle cx="11" cy="11" r="8"></circle> <line x1="21" y1="21" x2="16.65" y2="16.65"></line> </svg> </button> <button id="navbar__menu-button" aria-label="Menu" class="navbar__icon-item navbar_icon-item--visually-aligned" hidden > <svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" width="24" viewBox="0 0 24 24" fill="currentColor" > <path d="M3,6H21V8H3V6M3,11H21V13H3V11M3,16H21V18H3V16Z" /> </svg> </button> </div> <div id="navbar__backdrop" class="navbar__backdrop" ></div> </div> <div id="flash-message"></div> </nav> <nav id="trick"><div><dl> <dt><a href='/manual/en/getting-started.php'>Getting Started</a></dt> <dd><a href='/manual/en/introduction.php'>Introduction</a></dd> <dd><a href='/manual/en/tutorial.php'>A simple tutorial</a></dd> <dt><a href='/manual/en/langref.php'>Language Reference</a></dt> <dd><a href='/manual/en/language.basic-syntax.php'>Basic syntax</a></dd> <dd><a href='/manual/en/language.types.php'>Types</a></dd> <dd><a href='/manual/en/language.variables.php'>Variables</a></dd> <dd><a href='/manual/en/language.constants.php'>Constants</a></dd> <dd><a href='/manual/en/language.expressions.php'>Expressions</a></dd> <dd><a href='/manual/en/language.operators.php'>Operators</a></dd> <dd><a href='/manual/en/language.control-structures.php'>Control Structures</a></dd> <dd><a href='/manual/en/language.functions.php'>Functions</a></dd> <dd><a href='/manual/en/language.oop5.php'>Classes and Objects</a></dd> <dd><a href='/manual/en/language.namespaces.php'>Namespaces</a></dd> <dd><a href='/manual/en/language.enumerations.php'>Enumerations</a></dd> <dd><a href='/manual/en/language.errors.php'>Errors</a></dd> <dd><a href='/manual/en/language.exceptions.php'>Exceptions</a></dd> <dd><a href='/manual/en/language.fibers.php'>Fibers</a></dd> <dd><a href='/manual/en/language.generators.php'>Generators</a></dd> <dd><a href='/manual/en/language.attributes.php'>Attributes</a></dd> <dd><a href='/manual/en/language.references.php'>References Explained</a></dd> <dd><a href='/manual/en/reserved.variables.php'>Predefined Variables</a></dd> <dd><a href='/manual/en/reserved.exceptions.php'>Predefined Exceptions</a></dd> <dd><a href='/manual/en/reserved.interfaces.php'>Predefined Interfaces and Classes</a></dd> <dd><a href='/manual/en/reserved.attributes.php'>Predefined Attributes</a></dd> <dd><a href='/manual/en/context.php'>Context options and parameters</a></dd> <dd><a href='/manual/en/wrappers.php'>Supported Protocols and Wrappers</a></dd> </dl> <dl> <dt><a href='/manual/en/security.php'>Security</a></dt> <dd><a href='/manual/en/security.intro.php'>Introduction</a></dd> <dd><a href='/manual/en/security.general.php'>General considerations</a></dd> <dd><a href='/manual/en/security.cgi-bin.php'>Installed as CGI binary</a></dd> <dd><a href='/manual/en/security.apache.php'>Installed as an Apache module</a></dd> <dd><a href='/manual/en/security.sessions.php'>Session Security</a></dd> <dd><a href='/manual/en/security.filesystem.php'>Filesystem Security</a></dd> <dd><a href='/manual/en/security.database.php'>Database Security</a></dd> <dd><a href='/manual/en/security.errors.php'>Error Reporting</a></dd> <dd><a href='/manual/en/security.variables.php'>User Submitted Data</a></dd> <dd><a href='/manual/en/security.hiding.php'>Hiding PHP</a></dd> <dd><a href='/manual/en/security.current.php'>Keeping Current</a></dd> <dt><a href='/manual/en/features.php'>Features</a></dt> <dd><a href='/manual/en/features.http-auth.php'>HTTP authentication with PHP</a></dd> <dd><a href='/manual/en/features.cookies.php'>Cookies</a></dd> <dd><a href='/manual/en/features.sessions.php'>Sessions</a></dd> <dd><a href='/manual/en/features.file-upload.php'>Handling file uploads</a></dd> <dd><a href='/manual/en/features.remote-files.php'>Using remote files</a></dd> <dd><a href='/manual/en/features.connection-handling.php'>Connection handling</a></dd> <dd><a href='/manual/en/features.persistent-connections.php'>Persistent Database Connections</a></dd> <dd><a href='/manual/en/features.commandline.php'>Command line usage</a></dd> <dd><a href='/manual/en/features.gc.php'>Garbage Collection</a></dd> <dd><a href='/manual/en/features.dtrace.php'>DTrace Dynamic Tracing</a></dd> </dl> <dl> <dt><a href='/manual/en/funcref.php'>Function Reference</a></dt> <dd><a href='/manual/en/refs.basic.php.php'>Affecting PHP's Behaviour</a></dd> <dd><a href='/manual/en/refs.utilspec.audio.php'>Audio Formats Manipulation</a></dd> <dd><a href='/manual/en/refs.remote.auth.php'>Authentication Services</a></dd> <dd><a href='/manual/en/refs.utilspec.cmdline.php'>Command Line Specific Extensions</a></dd> <dd><a href='/manual/en/refs.compression.php'>Compression and Archive Extensions</a></dd> <dd><a href='/manual/en/refs.crypto.php'>Cryptography Extensions</a></dd> <dd><a href='/manual/en/refs.database.php'>Database Extensions</a></dd> <dd><a href='/manual/en/refs.calendar.php'>Date and Time Related Extensions</a></dd> <dd><a href='/manual/en/refs.fileprocess.file.php'>File System Related Extensions</a></dd> <dd><a href='/manual/en/refs.international.php'>Human Language and Character Encoding Support</a></dd> <dd><a href='/manual/en/refs.utilspec.image.php'>Image Processing and Generation</a></dd> <dd><a href='/manual/en/refs.remote.mail.php'>Mail Related Extensions</a></dd> <dd><a href='/manual/en/refs.math.php'>Mathematical Extensions</a></dd> <dd><a href='/manual/en/refs.utilspec.nontext.php'>Non-Text MIME Output</a></dd> <dd><a href='/manual/en/refs.fileprocess.process.php'>Process Control Extensions</a></dd> <dd><a href='/manual/en/refs.basic.other.php'>Other Basic Extensions</a></dd> <dd><a href='/manual/en/refs.remote.other.php'>Other Services</a></dd> <dd><a href='/manual/en/refs.search.php'>Search Engine Extensions</a></dd> <dd><a href='/manual/en/refs.utilspec.server.php'>Server Specific Extensions</a></dd> <dd><a href='/manual/en/refs.basic.session.php'>Session Extensions</a></dd> <dd><a href='/manual/en/refs.basic.text.php'>Text Processing</a></dd> <dd><a href='/manual/en/refs.basic.vartype.php'>Variable and Type Related Extensions</a></dd> <dd><a href='/manual/en/refs.webservice.php'>Web Services</a></dd> <dd><a href='/manual/en/refs.utilspec.windows.php'>Windows Only Extensions</a></dd> <dd><a href='/manual/en/refs.xml.php'>XML Manipulation</a></dd> <dd><a href='/manual/en/refs.ui.php'>GUI Extensions</a></dd> </dl> <dl> <dt>Keyboard Shortcuts</dt><dt>?</dt> <dd>This help</dd> <dt>j</dt> <dd>Next menu item</dd> <dt>k</dt> <dd>Previous menu item</dd> <dt>g p</dt> <dd>Previous man page</dd> <dt>g n</dt> <dd>Next man page</dd> <dt>G</dt> <dd>Scroll to bottom</dd> <dt>g g</dt> <dd>Scroll to top</dd> <dt>g h</dt> <dd>Goto homepage</dd> <dt>g s</dt> <dd>Goto search<br>(current page)</dd> <dt>/</dt> <dd>Focus search box</dd> </dl></div></nav> <div id="goto"> <div class="search"> <div class="text"></div> <div class="results"><ul></ul></div> </div> </div> <div id="breadcrumbs" class="clearfix"> <div id="breadcrumbs-inner"> <div class="next"> <a href="function.srand.php"> srand » </a> </div> <div class="prev"> <a href="function.random-bytes.php"> « random_bytes </a> </div> <ul> <li><a href='index.php'>PHP Manual</a></li> <li><a href='funcref.php'>Function Reference</a></li> <li><a href='refs.basic.other.php'>Other Basic Extensions</a></li> <li><a href='book.random.php'>Random</a></li> <li><a href='ref.random.php'>Random Functions</a></li> </ul> </div> </div> <div id="layout" class="clearfix"> <section id="layout-content"> <div class="page-tools"> <div class="change-language"> <form action="/manual/change.php" method="get" id="changelang" name="changelang"> <fieldset> <label for="changelang-langs">Change language:</label> <select onchange="document.changelang.submit()" name="page" id="changelang-langs"> <option value='en/function.random-int.php' selected="selected">English</option> <option value='de/function.random-int.php'>German</option> <option value='es/function.random-int.php'>Spanish</option> <option value='fr/function.random-int.php'>French</option> <option value='it/function.random-int.php'>Italian</option> <option value='ja/function.random-int.php'>Japanese</option> <option value='pt_BR/function.random-int.php'>Brazilian Portuguese</option> <option value='ru/function.random-int.php'>Russian</option> <option value='tr/function.random-int.php'>Turkish</option> <option value='uk/function.random-int.php'>Ukrainian</option> <option value='zh/function.random-int.php'>Chinese (Simplified)</option> <option value='help-translate.php'>Other</option> </select> </fieldset> </form> </div> </div><div id="function.random-int" class="refentry"> <div class="refnamediv"> <h1 class="refname">random_int</h1> <p class="verinfo">(PHP 7, PHP 8)</p><p class="refpurpose"><span class="refname">random_int</span> — <span class="dc-title">Get a cryptographically secure, uniformly selected integer</span></p> </div> <div class="refsect1 description" id="refsect1-function.random-int-description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="methodname"><strong>random_int</strong></span>(<span class="methodparam"><span class="type"><a href="language.types.integer.php" class="type int">int</a></span> <code class="parameter">$min</code></span>, <span class="methodparam"><span class="type"><a href="language.types.integer.php" class="type int">int</a></span> <code class="parameter">$max</code></span>): <span class="type"><a href="language.types.integer.php" class="type int">int</a></span></div> <p class="para rdfs-comment"> Generates a uniformly selected integer between the given minimum and maximum. </p> <p class="para"> The randomness generated by this function is suitable for all applications, including the generation of long-term secrets, such as encryption keys. </p> <p class="para"> The sources of randomness in the order of priority are as follows: </p> <ul class="itemizedlist"> <li class="listitem"> <p class="para"> Linux: <a href="http://man7.org/linux/man-pages/man2/getrandom.2.html" class="link external">» getrandom()</a>, <var class="filename">/dev/urandom</var> </p> </li> <li class="listitem"> <p class="para"> FreeBSD >= 12 (PHP >= 7.3): <a href="http://man7.org/linux/man-pages/man2/getrandom.2.html" class="link external">» getrandom()</a>, <var class="filename">/dev/urandom</var> </p> </li> <li class="listitem"> <p class="para"> Windows (PHP >= 7.2): <a href="https://docs.microsoft.com/en-us/windows/desktop/SecCNG/cng-portal" class="link external">» CNG-API</a> </p> <p class="para"> Windows: <a href="https://msdn.microsoft.com/en-us/library/windows/desktop/aa379942(v=vs.85).aspx" class="link external">» CryptGenRandom</a> </p> </li> <li class="listitem"> <p class="para"> macOS (PHP >= 8.2; >= 8.1.9; >= 8.0.22 if CCRandomGenerateBytes is available at compile time): CCRandomGenerateBytes() </p> <p class="para"> macOS (PHP >= 8.1; >= 8.0.2): arc4random_buf(), <var class="filename">/dev/urandom</var> </p> </li> <li class="listitem"> <p class="para"> NetBSD >= 7 (PHP >= 7.1; >= 7.0.1): arc4random_buf(), <var class="filename">/dev/urandom</var> </p> </li> <li class="listitem"> <p class="para"> OpenBSD >= 5.5 (PHP >= 7.1; >= 7.0.1): arc4random_buf(), <var class="filename">/dev/urandom</var> </p> </li> <li class="listitem"> <p class="para"> DragonflyBSD (PHP >= 8.1): <a href="http://man7.org/linux/man-pages/man2/getrandom.2.html" class="link external">» getrandom()</a>, <var class="filename">/dev/urandom</var> </p> </li> <li class="listitem"> <p class="para"> Solaris (PHP >= 8.1): <a href="http://man7.org/linux/man-pages/man2/getrandom.2.html" class="link external">» getrandom()</a>, <var class="filename">/dev/urandom</var> </p> </li> <li class="listitem"> <span class="simpara"> Any combination of operating system and PHP version not previously mentioned: <var class="filename">/dev/urandom</var> </span> </li> <li class="listitem"> <span class="simpara"> If none of the sources are available or they all fail to generate randomness, then a <span class="classname"><a href="class.random-randomexception.php" class="classname">Random\RandomException</a></span> will be thrown. </span> </li> </ul> <blockquote class="note"><p><strong class="note">Note</strong>: <span class="simpara"> Although this function was added to PHP in PHP 7.0, a <a href="https://github.com/paragonie/random_compat" class="link external">» userland implementation</a> is available for PHP 5.2 to 5.6, inclusive. </span> </p></blockquote> </div> <div class="refsect1 parameters" id="refsect1-function.random-int-parameters"> <h3 class="title">Parameters</h3> <dl> <dt><code class="parameter">min</code></dt> <dd> <p class="para"> The lowest value to be returned. </p> </dd> <dt><code class="parameter">max</code></dt> <dd> <p class="para"> The highest value to be returned. </p> </dd> </dl> </div> <div class="refsect1 returnvalues" id="refsect1-function.random-int-returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> A cryptographically secure, uniformly selected integer from the closed interval [<code class="parameter">min</code>, <code class="parameter">max</code>]. Both <code class="parameter">min</code> and <code class="parameter">max</code> are possible return values. </p> </div> <div class="refsect1 errors" id="refsect1-function.random-int-errors"> <h3 class="title">Errors/Exceptions</h3> <ul class="itemizedlist"> <li class="listitem"> <span class="simpara"> If an appropriate source of randomness cannot be found, a <span class="classname"><a href="class.random-randomexception.php" class="classname">Random\RandomException</a></span> will be thrown. </span> </li> <li class="listitem"> <span class="simpara"> If <code class="parameter">max</code> is less than <code class="parameter">min</code>, a <span class="classname"><a href="class.valueerror.php" class="classname">ValueError</a></span> will be thrown. </span> </li> </ul> </div> <div class="refsect1 changelog" id="refsect1-function.random-int-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>8.2.0</td> <td> In case of a <abbr title="Cryptographically Secure PseudoRandom Number Generator">CSPRNG</abbr> failure, this function will now throw a <span class="classname"><a href="class.random-randomexception.php" class="classname">Random\RandomException</a></span>. Previously a plain <span class="classname"><a href="class.exception.php" class="classname">Exception</a></span> was thrown. </td> </tr> </tbody> </table> </div> <div class="refsect1 examples" id="refsect1-function.random-int-examples"> <h3 class="title">Examples</h3> <div class="example" id="random-int.example.basic"> <p><strong>Example #1 <span class="function"><strong>random_int()</strong></span> example</strong></p> <div class="example-contents"> <div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br />var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">random_int</span><span style="color: #007700">(</span><span style="color: #0000BB">100</span><span style="color: #007700">, </span><span style="color: #0000BB">999</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">random_int</span><span style="color: #007700">(-</span><span style="color: #0000BB">1000</span><span style="color: #007700">, </span><span style="color: #0000BB">0</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="examplescode"><pre class="examplescode">int(248) int(-898)</pre> </div> </div> </div> </div> <div class="refsect1 seealso" id="refsect1-function.random-int-seealso"> <h3 class="title">See Also</h3> <ul class="simplelist"> <li><span class="methodname"><a href="random-randomizer.getint.php" class="methodname" rel="rdfs-seeAlso">Random\Randomizer::getInt()</a> - Get a uniformly selected integer</span></li> <li><span class="function"><a href="function.random-bytes.php" class="function" rel="rdfs-seeAlso">random_bytes()</a> - Get cryptographically secure random bytes</span></li> </ul> </div> </div> <div class="contribute"> <h3 class="title">Found A Problem?</h3> <div> </div> <div class="edit-bug"> <a href="https://github.com/php/doc-base/blob/master/README.md" title="This will take you to our contribution guidelines on GitHub" target="_blank" rel="noopener noreferrer">Learn How To Improve This Page</a> • <a href="https://github.com/php/doc-en/blob/master/reference/random/functions/random-int.xml">Submit a Pull Request</a> • <a href="https://github.com/php/doc-en/issues/new?body=From%20manual%20page:%20https:%2F%2Fphp.net%2Ffunction.random-int%0A%0A---">Report a Bug</a> </div> </div><section id="usernotes"> <div class="head"> <span class="action"><a href="/manual/add-note.php?sect=function.random-int&repo=en&redirect=https://www.php.net/manual/en/function.random-int.php">＋<small>add a note</small></a></span> <h3 class="title">User Contributed Notes <span class="count">4 notes</span></h3> </div><div id="allnotes"> <div class="note" id="119670"> <div class="votes"> <div id="Vu119670"> <a href="/manual/vote-note.php?id=119670&page=function.random-int&vote=up" title="Vote up!" class="usernotes-voteu">up</a> </div> <div id="Vd119670"> <a href="/manual/vote-note.php?id=119670&page=function.random-int&vote=down" title="Vote down!" class="usernotes-voted">down</a> </div> <div class="tally" id="V119670" title="56% like this..."> 15 </div> </div> <a href="#119670" class="name"> <strong class="user"><em>s rotondo90 at gmail com</em></strong></a><a class="genanchor" href="#119670"> ¶</a><div class="date" title="2016-07-30 01:11"><strong>8 years ago</strong></div> <div class="text" id="Hcom119670"> <div class="phpcode"><code><span class="html">Here is a simple backporting function, it works for PHP >= 5.1<br /><br /><span class="default"><?php<br /></span><span class="keyword">if (!</span><span class="default">function_exists</span><span class="keyword">(</span><span class="string">'random_int'</span><span class="keyword">)) {<br /> function </span><span class="default">random_int</span><span class="keyword">(</span><span class="default">$min</span><span class="keyword">, </span><span class="default">$max</span><span class="keyword">) {<br /> if (!</span><span class="default">function_exists</span><span class="keyword">(</span><span class="string">'mcrypt_create_iv'</span><span class="keyword">)) {<br /> </span><span class="default">trigger_error</span><span class="keyword">(<br /> </span><span class="string">'mcrypt must be loaded for random_int to work'</span><span class="keyword">, <br /> </span><span class="default">E_USER_WARNING<br /> </span><span class="keyword">);<br /> return </span><span class="default">null</span><span class="keyword">;<br /> }<br /> <br /> if (!</span><span class="default">is_int</span><span class="keyword">(</span><span class="default">$min</span><span class="keyword">) || !</span><span class="default">is_int</span><span class="keyword">(</span><span class="default">$max</span><span class="keyword">)) {<br /> </span><span class="default">trigger_error</span><span class="keyword">(</span><span class="string">'$min and $max must be integer values'</span><span class="keyword">, </span><span class="default">E_USER_NOTICE</span><span class="keyword">);<br /> </span><span class="default">$min </span><span class="keyword">= (int)</span><span class="default">$min</span><span class="keyword">;<br /> </span><span class="default">$max </span><span class="keyword">= (int)</span><span class="default">$max</span><span class="keyword">;<br /> }<br /> <br /> if (</span><span class="default">$min </span><span class="keyword">> </span><span class="default">$max</span><span class="keyword">) {<br /> </span><span class="default">trigger_error</span><span class="keyword">(</span><span class="string">'$max can\'t be lesser than $min'</span><span class="keyword">, </span><span class="default">E_USER_WARNING</span><span class="keyword">);<br /> return </span><span class="default">null</span><span class="keyword">;<br /> }<br /> <br /> </span><span class="default">$range </span><span class="keyword">= </span><span class="default">$counter </span><span class="keyword">= </span><span class="default">$max </span><span class="keyword">- </span><span class="default">$min</span><span class="keyword">;<br /> </span><span class="default">$bits </span><span class="keyword">= </span><span class="default">1</span><span class="keyword">;<br /> <br /> while (</span><span class="default">$counter </span><span class="keyword">>>= </span><span class="default">1</span><span class="keyword">) {<br /> ++</span><span class="default">$bits</span><span class="keyword">;<br /> }<br /> <br /> </span><span class="default">$bytes </span><span class="keyword">= (int)</span><span class="default">max</span><span class="keyword">(</span><span class="default">ceil</span><span class="keyword">(</span><span class="default">$bits</span><span class="keyword">/</span><span class="default">8</span><span class="keyword">), </span><span class="default">1</span><span class="keyword">);<br /> </span><span class="default">$bitmask </span><span class="keyword">= </span><span class="default">pow</span><span class="keyword">(</span><span class="default">2</span><span class="keyword">, </span><span class="default">$bits</span><span class="keyword">) - </span><span class="default">1</span><span class="keyword">;<br /> <br /> if (</span><span class="default">$bitmask </span><span class="keyword">>= </span><span class="default">PHP_INT_MAX</span><span class="keyword">) {<br /> </span><span class="default">$bitmask </span><span class="keyword">= </span><span class="default">PHP_INT_MAX</span><span class="keyword">;<br /> }<br /> <br /> do {<br /> </span><span class="default">$result </span><span class="keyword">= </span><span class="default">hexdec</span><span class="keyword">(<br /> </span><span class="default">bin2hex</span><span class="keyword">(<br /> </span><span class="default">mcrypt_create_iv</span><span class="keyword">(</span><span class="default">$bytes</span><span class="keyword">, </span><span class="default">MCRYPT_DEV_URANDOM</span><span class="keyword">)<br /> )<br /> ) & </span><span class="default">$bitmask</span><span class="keyword">;<br /> } while (</span><span class="default">$result </span><span class="keyword">> </span><span class="default">$range</span><span class="keyword">);<br /> <br /> return </span><span class="default">$result </span><span class="keyword">+ </span><span class="default">$min</span><span class="keyword">;<br /> }<br />}<br /></span><span class="default">?><br /></span><br />Randomness test<br /><br /><span class="default"><?php<br />$max </span><span class="keyword">= </span><span class="default">100</span><span class="keyword">; </span><span class="comment">// number of random values<br /></span><span class="default">$test </span><span class="keyword">= </span><span class="default">1000000</span><span class="keyword">;<br /><br /></span><span class="default">$array </span><span class="keyword">= </span><span class="default">array_fill</span><span class="keyword">(</span><span class="default">0</span><span class="keyword">, </span><span class="default">$max</span><span class="keyword">, </span><span class="default">0</span><span class="keyword">);<br /><br />for (</span><span class="default">$i </span><span class="keyword">= </span><span class="default">0</span><span class="keyword">; </span><span class="default">$i </span><span class="keyword">< </span><span class="default">$test</span><span class="keyword">; ++</span><span class="default">$i</span><span class="keyword">) {<br /> ++</span><span class="default">$array</span><span class="keyword">[</span><span class="default">random_int</span><span class="keyword">(</span><span class="default">0</span><span class="keyword">, </span><span class="default">$max</span><span class="keyword">-</span><span class="default">1</span><span class="keyword">)];<br />}<br /><br />function </span><span class="default">arrayFormatResult</span><span class="keyword">(&</span><span class="default">$item</span><span class="keyword">) {<br /> global </span><span class="default">$test</span><span class="keyword">, </span><span class="default">$max</span><span class="keyword">; </span><span class="comment">// try to avoid this nowdays ;)<br /> <br /> </span><span class="default">$perc </span><span class="keyword">= (</span><span class="default">$item</span><span class="keyword">/(</span><span class="default">$test</span><span class="keyword">/</span><span class="default">$max</span><span class="keyword">))-</span><span class="default">1</span><span class="keyword">;<br /> </span><span class="default">$item </span><span class="keyword">.= </span><span class="string">' '</span><span class="keyword">. </span><span class="default">number_format</span><span class="keyword">(</span><span class="default">$perc</span><span class="keyword">, </span><span class="default">4</span><span class="keyword">, </span><span class="string">'.'</span><span class="keyword">, </span><span class="string">''</span><span class="keyword">) .</span><span class="string">'%'</span><span class="keyword">;<br />}<br /><br /></span><span class="default">array_walk</span><span class="keyword">(</span><span class="default">$array</span><span class="keyword">, </span><span class="string">'arrayFormatResult'</span><span class="keyword">);<br /><br /></span><span class="default">print_r</span><span class="keyword">(</span><span class="default">$array</span><span class="keyword">);<br /></span><span class="default">?></span></span></code></div> </div> </div> <div class="note" id="125333"> <div class="votes"> <div id="Vu125333"> <a href="/manual/vote-note.php?id=125333&page=function.random-int&vote=up" title="Vote up!" class="usernotes-voteu">up</a> </div> <div id="Vd125333"> <a href="/manual/vote-note.php?id=125333&page=function.random-int&vote=down" title="Vote down!" class="usernotes-voted">down</a> </div> <div class="tally" id="V125333" title="54% like this..."> 4 </div> </div> <a href="#125333" class="name"> <strong class="user"><em>bens at effortlessis dot com</em></strong></a><a class="genanchor" href="#125333"> ¶</a><div class="date" title="2020-09-05 04:21"><strong>4 years ago</strong></div> <div class="text" id="Hcom125333"> <div class="phpcode"><code><span class="html">On my system (5th gen i7) random_int() takes about 14x longer to do the same number of calculations than rand(). <br /><br />for ($i=0; $i<10000000; $i++)<br /> $x = rand(1, PHP_INT_MAX);<br /><br />Takes 0.86 seconds for rand(), 12.29 seconds for random_int(). So use random_int() somewhat sparingly. <br /><br />If it's not really important to be truly random, use rand() instead, especially in a tight loop.</span></code></div> </div> </div> <div class="note" id="124010"> <div class="votes"> <div id="Vu124010"> <a href="/manual/vote-note.php?id=124010&page=function.random-int&vote=up" title="Vote up!" class="usernotes-voteu">up</a> </div> <div id="Vd124010"> <a href="/manual/vote-note.php?id=124010&page=function.random-int&vote=down" title="Vote down!" class="usernotes-voted">down</a> </div> <div class="tally" id="V124010" title="50% like this..."> 0 </div> </div> <a href="#124010" class="name"> <strong class="user"><em>ccb_bc at hotmail dot com</em></strong></a><a class="genanchor" href="#124010"> ¶</a><div class="date" title="2019-07-04 03:02"><strong>5 years ago</strong></div> <div class="text" id="Hcom124010"> <div class="phpcode"><code><span class="html"><span class="default"><?php <br /> </span><span class="comment">// PHP >= 7<br /> </span><span class="keyword">function </span><span class="default">str_rand</span><span class="keyword">(</span><span class="default">int $length </span><span class="keyword">= </span><span class="default">16</span><span class="keyword">){<br /> </span><span class="default">$x </span><span class="keyword">= </span><span class="string">''</span><span class="keyword">;<br /> for(</span><span class="default">$i </span><span class="keyword">= </span><span class="default">1</span><span class="keyword">; </span><span class="default">$i </span><span class="keyword"><= </span><span class="default">$length</span><span class="keyword">; </span><span class="default">$i</span><span class="keyword">++){<br /> </span><span class="default">$x </span><span class="keyword">.= </span><span class="default">dechex</span><span class="keyword">(</span><span class="default">random_int</span><span class="keyword">(</span><span class="default">0</span><span class="keyword">,</span><span class="default">255</span><span class="keyword">));<br /> }<br /> return </span><span class="default">substr</span><span class="keyword">(</span><span class="default">$x</span><span class="keyword">, </span><span class="default">0</span><span class="keyword">, </span><span class="default">$length</span><span class="keyword">);<br /> }<br /> </span><span class="default">var_dump</span><span class="keyword">(</span><span class="default">str_rand</span><span class="keyword">());<br /></span><span class="default">?></span></span></code></div> </div> </div> <div class="note" id="128851"> <div class="votes"> <div id="Vu128851"> <a href="/manual/vote-note.php?id=128851&page=function.random-int&vote=up" title="Vote up!" class="usernotes-voteu">up</a> </div> <div id="Vd128851"> <a href="/manual/vote-note.php?id=128851&page=function.random-int&vote=down" title="Vote down!" class="usernotes-voted">down</a> </div> <div class="tally" id="V128851" title="40% like this..."> -1 </div> </div> <a href="#128851" class="name"> <strong class="user"><em>Hayley Watson</em></strong></a><a class="genanchor" href="#128851"> ¶</a><div class="date" title="2023-09-02 12:51"><strong>1 year ago</strong></div> <div class="text" id="Hcom128851"> <div class="phpcode"><code><span class="html">A small function for generating version 4 GUIDs.<br /><br /><span class="default"><?php<br /></span><span class="keyword">function </span><span class="default">v4uuid</span><span class="keyword">()<br />{<br /> </span><span class="default">$a </span><span class="keyword">= </span><span class="default">str_pad</span><span class="keyword">(</span><span class="default">dechex</span><span class="keyword">(</span><span class="default">random_int</span><span class="keyword">(</span><span class="default">0x0000_0000</span><span class="keyword">, </span><span class="default">0xffff_ffff</span><span class="keyword">)), </span><span class="string">'0'</span><span class="keyword">, </span><span class="default">STR_PAD_LEFT</span><span class="keyword">);<br /> </span><span class="default">$b </span><span class="keyword">= </span><span class="default">str_pad</span><span class="keyword">(</span><span class="default">dechex</span><span class="keyword">(</span><span class="default">random_int</span><span class="keyword">(</span><span class="default">0x0000</span><span class="keyword">, </span><span class="default">0xffff</span><span class="keyword">)), </span><span class="string">'0'</span><span class="keyword">, </span><span class="default">STR_PAD_LEFT</span><span class="keyword">);<br /> </span><span class="default">$c </span><span class="keyword">= </span><span class="default">dechex</span><span class="keyword">(</span><span class="default">random_int</span><span class="keyword">(</span><span class="default">0x4000</span><span class="keyword">, </span><span class="default">0x4fff</span><span class="keyword">));<br /> </span><span class="default">$d </span><span class="keyword">= </span><span class="default">dechex</span><span class="keyword">(</span><span class="default">random_int</span><span class="keyword">(</span><span class="default">0x8000</span><span class="keyword">, </span><span class="default">0xbfff</span><span class="keyword">));<br /> </span><span class="default">$e </span><span class="keyword">= </span><span class="default">str_pad</span><span class="keyword">(</span><span class="default">dechex</span><span class="keyword">(</span><span class="default">random_int</span><span class="keyword">(</span><span class="default">0x0000_0000_0000</span><span class="keyword">, </span><span class="default">0xffff_ffff_ffff</span><span class="keyword">)), </span><span class="string">'0'</span><span class="keyword">, </span><span class="default">STR_PAD_LEFT</span><span class="keyword">);<br /> return </span><span class="string">"</span><span class="default">$a</span><span class="string">-</span><span class="default">$b</span><span class="string">-</span><span class="default">$c</span><span class="string">-</span><span class="default">$d</span><span class="string">-</span><span class="default">$e</span><span class="string">"</span><span class="keyword">;<br />}<br /></span><span class="default">?></span></span></code></div> </div> </div></div> <div class="foot"><a href="/manual/add-note.php?sect=function.random-int&repo=en&redirect=https://www.php.net/manual/en/function.random-int.php">＋<small>add a note</small></a></div> </section> </section> <aside class='layout-menu'> <ul class='parent-menu-list'> <li> <a href="ref.random.php">Random Functions</a> <ul class='child-menu-list'> <li class=""> <a href="function.getrandmax.php" title="getrandmax">getrandmax</a> </li> <li class=""> <a href="function.mt-getrandmax.php" title="mt_getrandmax">mt_getrandmax</a> </li> <li class=""> <a href="function.mt-rand.php" title="mt_rand">mt_rand</a> </li> <li class=""> <a href="function.mt-srand.php" title="mt_srand">mt_srand</a> </li> <li class=""> <a href="function.rand.php" title="rand">rand</a> </li> <li class=""> <a href="function.random-bytes.php" title="random_bytes">random_bytes</a> </li> <li class="current"> <a href="function.random-int.php" title="random_int">random_int</a> </li> <li class=""> <a href="function.srand.php" title="srand">srand</a> </li> </ul> </li> <li> <span class="header">Deprecated</span> <ul class="child-menu-list"> <li class=""> <a href="function.lcg-value.php" title="lcg_value">lcg_value</a> </li> </ul> </li> </ul> </aside> </div> <footer> <div class="container footer-content"> <div class="row-fluid"> <ul class="footmenu"> <li><a href="/manual/en/copyright.php">Copyright © 2001-2024 The PHP Documentation Group</a></li> <li><a href="/my.php">My PHP.net</a></li> <li><a href="/contact.php">Contact</a></li> <li><a href="/sites.php">Other PHP.net sites</a></li> <li><a href="/privacy.php">Privacy policy</a></li> </ul> </div> </div> </footer> <script src="/cached.php?t=1731172202&f=/js/ext/jquery-3.6.0.min.js"></script> <script src="/cached.php?t=1723177202&f=/js/ext/FuzzySearch.min.js"></script> <script src="/cached.php?t=1707321815&f=/js/ext/mousetrap.min.js"></script> <script src="/cached.php?t=1707321815&f=/js/ext/jquery.scrollTo.min.js"></script> <script src="/cached.php?t=1730558402&f=/js/search.js"></script> <script src="/cached.php?t=1731172202&f=/js/common.js"></script> <a id="toTop" href="javascript:;"><span id="toTopHover"></span><img width="40" height="40" alt="To Top" src="/images/to-top@2x.png"></a> <div id="search-modal__backdrop" class="search-modal__backdrop"> <div role="dialog" aria-label="Search modal" id="search-modal" class="search-modal" > <div class="search-modal__header"> <div class="search-modal__form"> <div class="search-modal__input-icon">  <svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" width="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" > <circle cx="11" cy="11" r="8"></circle> <line x1="21" y1="21" x2="16.65" y2="16.65"></line> </svg> </div> <input type="search" id="search-modal__input" class="search-modal__input" placeholder="Search docs" aria-label="Search docs" /> </div> <button aria-label="Close" class="search-modal__close">  <svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" width="24" viewBox="0 0 24 24" > <path d="M19,6.41L17.59,5L12,10.59L6.41,5L5,6.41L10.59,12L5,17.59L6.41,19L12,13.41L17.59,19L19,17.59L13.41,12L19,6.41Z"/> </svg> </button> </div> <div role="listbox" aria-label="Search results" id="search-modal__results" class="search-modal__results" ></div> <div class="search-modal__helper-text"> <div> <kbd>↑</kbd> and <kbd>↓</kbd> to navigate • <kbd>Enter</kbd> to select • <kbd>Esc</kbd> to close </div> <div> Press <kbd>Enter</kbd> without selection to search using Google </div> </div> </div> </div> </body> </html>

CINXE.COM

PHP: random_int - Manual