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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html> <head> <title>Compares two "PHP-standardized" version number strings</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> </head> <body><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.sys-get-temp-dir.html">sys_get_temp_dir</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.zend-logo-guid.html">zend_logo_guid</a></div> <div class="up"><a href="ref.info.html">PHP Options/Info Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="function.version-compare" class="refentry"> <div class="refnamediv"> <h1 class="refname">version_compare</h1> <p class="verinfo">(PHP 4 >= 4.0.7, PHP 5)</p><p class="refpurpose"><span class="refname">version_compare</span> — <span class="dc-title">Compares two "PHP-standardized" version number strings</span></p> </div> <div class="refsect1 description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <span class="methodname"><b><b>version_compare</b></b></span> ( <span class="methodparam"><span class="type">string</span> <tt class="parameter">$version1</tt></span> , <span class="methodparam"><span class="type">string</span> <tt class="parameter">$version2</tt></span> [, <span class="methodparam"><span class="type">string</span> <tt class="parameter">$operator</tt></span> ] )</div> <p class="para rdfs-comment"> <b>version_compare()</b> compares two "PHP-standardized" version number strings. This is useful if you would like to write programs working only on some versions of PHP. </p> <p class="para"> The function first replaces <i>_</i>, <i>-</i> and <i>+</i> with a dot <i>.</i> in the version strings and also inserts dots <i>.</i> before and after any non number so that for example '4.3.2RC1' becomes '4.3.2.RC.1'. Then it splits the results like if you were using explode('.', $ver). Then it compares the parts starting from left to right. If a part contains special version strings these are handled in the following order: <i>dev</i> < <i>alpha</i> = <i>a</i> < <i>beta</i> = <i>b</i> < <i>RC</i> < <i>pl</i>. This way not only versions with different levels like '4.1' and '4.1.2' can be compared but also any PHP specific version containing development state. </p> </div> <div class="refsect1 parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt> <span class="term"><i><tt class="parameter">version1</tt></i></span> <dd> <p class="para"> First version number. </p> </dd> </dt> <dt> <span class="term"><i><tt class="parameter">version2</tt></i></span> <dd> <p class="para"> Second version number. </p> </dd> </dt> <dt> <span class="term"><i><tt class="parameter">operator</tt></i></span> <dd> <p class="para"> If you specify the third optional <i><tt class="parameter">operator</tt></i> argument, you can test for a particular relationship. The possible operators are: <i><</i>, <i>lt</i>, <i><=</i>, <i>le</i>, <i>></i>, <i>gt</i>, <i>>=</i>, <i>ge</i>, <i>==</i>, <i>=</i>, <i>eq</i>, <i>!=</i>, <i><></i>, <i>ne</i> respectively. </p> <p class="para"> This parameter is case-sensitive, so values should be lowercase. </p> </dd> </dt> </dl> </p> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> By default, <b>version_compare()</b> returns <i>-1</i> if the first version is lower than the second, <i>0</i> if they are equal, and <i>1</i> if the second is lower. </p> <p class="para"> When using the optional <i><tt class="parameter">operator</tt></i> argument, the function will return <b><tt>TRUE</tt></b> if the relationship is the one specified by the operator, <b><tt>FALSE</tt></b> otherwise. </p> </div> <div class="refsect1 examples"> <h3 class="title">Examples</h3> <p class="para"> The examples below use the <b><tt>PHP_VERSION</tt></b> constant, because it contains the value of the PHP version that is executing the code. </p> <p class="para"> <div class="example"> <p><b>Example #1 <b>version_compare()</b> examples</b></p> <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br /></span><span style="color: #007700">if (</span><span style="color: #0000BB">version_compare</span><span style="color: #007700">(</span><span style="color: #0000BB">PHP_VERSION</span><span style="color: #007700">, </span><span style="color: #DD0000">'6.0.0'</span><span style="color: #007700">) === </span><span style="color: #0000BB">1</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">'I am at least PHP version 6.0.0, my version: ' </span><span style="color: #007700">. </span><span style="color: #0000BB">PHP_VERSION </span><span style="color: #007700">. </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />}<br /><br />if (</span><span style="color: #0000BB">version_compare</span><span style="color: #007700">(</span><span style="color: #0000BB">PHP_VERSION</span><span style="color: #007700">, </span><span style="color: #DD0000">'5.3.0'</span><span style="color: #007700">) === </span><span style="color: #0000BB">1</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">'I am at least PHP version 5.3.0, my version: ' </span><span style="color: #007700">. </span><span style="color: #0000BB">PHP_VERSION </span><span style="color: #007700">. </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />}<br /><br />if (</span><span style="color: #0000BB">version_compare</span><span style="color: #007700">(</span><span style="color: #0000BB">PHP_VERSION</span><span style="color: #007700">, </span><span style="color: #DD0000">'5.0.0'</span><span style="color: #007700">, </span><span style="color: #DD0000">'>'</span><span style="color: #007700">)) {<br /> echo </span><span style="color: #DD0000">'I am using PHP 5, my version: ' </span><span style="color: #007700">. </span><span style="color: #0000BB">PHP_VERSION </span><span style="color: #007700">. </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />}<br /><br />if (</span><span style="color: #0000BB">version_compare</span><span style="color: #007700">(</span><span style="color: #0000BB">PHP_VERSION</span><span style="color: #007700">, </span><span style="color: #DD0000">'5.0.0'</span><span style="color: #007700">, </span><span style="color: #DD0000">'<'</span><span style="color: #007700">)) {<br /> echo </span><span style="color: #DD0000">'I am using PHP 4, my version: ' </span><span style="color: #007700">. </span><span style="color: #0000BB">PHP_VERSION </span><span style="color: #007700">. </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?></span></span></code></div> </div> </div> </p> </div> <div class="refsect1 notes"> <h3 class="title">Notes</h3> <blockquote><p><b class="note">Note</b>: The <b><tt>PHP_VERSION</tt></b> constant holds current PHP version. <br /> </p></blockquote> <blockquote><p><b class="note">Note</b>: Note that pre-release versions, such as 5.3.0-dev, are considered lower than their final release counterparts (like 5.3.0). <br /> </p></blockquote> </div> <div class="refsect1 seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"><a href="function.phpversion.html" class="function" rel="rdfs-seeAlso">phpversion()</a></li> <li class="member"><a href="function.php-uname.html" class="function" rel="rdfs-seeAlso">php_uname()</a></li> <li class="member"><a href="function.function-exists.html" class="function" rel="rdfs-seeAlso">function_exists()</a></li> </ul> </p> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; 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