<!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>Replace regular expression</title> </head> <body><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="ref.regex.html">POSIX Regex Functions</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.ereg.html">ereg</a></div> <div class="up"><a href="ref.regex.html">POSIX Regex Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div><hr /><div id="function.ereg-replace" class="refentry"> <div class="refnamediv"> <h1 class="refname">ereg_replace</h1> <p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">ereg_replace</span> — <span class="dc-title">Replace regular expression</span></p> </div> <div class="refsect1 description" id="refsect1-function.ereg-replace-description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">string</span> <span class="methodname"><strong>ereg_replace</strong></span> ( <span class="methodparam"><span class="type">string</span> <code class="parameter">$pattern</code></span> , <span class="methodparam"><span class="type">string</span> <code class="parameter">$replacement</code></span> , <span class="methodparam"><span class="type">string</span> <code class="parameter">$string</code></span> )</div> <p class="simpara"> This function scans <em><code class="parameter">string</code></em> for matches to <em><code class="parameter">pattern</code></em>, then replaces the matched text with <em><code class="parameter">replacement</code></em>. </p> <div class="warning"><strong class="warning">Warning</strong><p class="simpara">This function has been <em class="emphasis">DEPRECATED</em> as of PHP 5.3.0. Relying on this feature is highly discouraged.</p></div> </div> <div class="refsect1 parameters" id="refsect1-function.ereg-replace-parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt> <span class="term"><em><code class="parameter">pattern</code></em></span> <dd> <p class="para"> A POSIX extended regular expression. </p> </dd> </dt> <dt> <span class="term"><em><code class="parameter">replacement</code></em></span> <dd> <p class="para"> If <em><code class="parameter">pattern</code></em> contains parenthesized substrings, <em><code class="parameter">replacement</code></em> may contain substrings of the form <em>\<span class="replaceable">digit</span></em>, which will be replaced by the text matching the digit'th parenthesized substring; <em>\0</em> will produce the entire contents of string. Up to nine substrings may be used. Parentheses may be nested, in which case they are counted by the opening parenthesis. </p> </dd> </dt> <dt> <span class="term"><em><code class="parameter">string</code></em></span> <dd> <p class="para"> The input string. </p> </dd> </dt> </dl> </p> </div> <div class="refsect1 returnvalues" id="refsect1-function.ereg-replace-returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> The modified string is returned. If no matches are found in <em><code class="parameter">string</code></em>, then it will be returned unchanged. </p> </div> <div class="refsect1 examples" id="refsect1-function.ereg-replace-examples"> <h3 class="title">Examples</h3> <p class="para"> For example, the following code snippet prints "This was a test" three times: </p> <p class="para"> <div class="example" id="example-4806"> <p><strong>Example #1 <span class="function"><strong>ereg_replace()</strong></span> example</strong></p> <div class="example-contents"> <div class="phpcode"><code><span style="color: #000000"> <span style="color: #0000BB"><?php<br /><br />$string </span><span style="color: #007700">= </span><span style="color: #DD0000">"This is a test"</span><span style="color: #007700">;<br />echo </span><span style="color: #0000BB">str_replace</span><span style="color: #007700">(</span><span style="color: #DD0000">" is"</span><span style="color: #007700">, </span><span style="color: #DD0000">" was"</span><span style="color: #007700">, </span><span style="color: #0000BB">$string</span><span style="color: #007700">);<br />echo </span><span style="color: #0000BB">ereg_replace</span><span style="color: #007700">(</span><span style="color: #DD0000">"( )is"</span><span style="color: #007700">, </span><span style="color: #DD0000">"\\1was"</span><span style="color: #007700">, </span><span style="color: #0000BB">$string</span><span style="color: #007700">);<br />echo </span><span style="color: #0000BB">ereg_replace</span><span style="color: #007700">(</span><span style="color: #DD0000">"(( )is)"</span><span style="color: #007700">, </span><span style="color: #DD0000">"\\2was"</span><span style="color: #007700">, </span><span style="color: #0000BB">$string</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">?></span> </span> </code></div> </div> </div> </p> <p class="para"> One thing to take note of is that if you use an integer value as the <em><code class="parameter">replacement</code></em> parameter, you may not get the results you expect. This is because <span class="function"><strong>ereg_replace()</strong></span> will interpret the number as the ordinal value of a character, and apply that. For instance: </p> <p class="para"> <div class="example" id="example-4807"> <p><strong>Example #2 <span class="function"><strong>ereg_replace()</strong></span> example</strong></p> <div class="example-contents"> <div class="phpcode"><code><span style="color: #000000"> <span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">/* This will not work as expected. */<br /></span><span style="color: #0000BB">$num </span><span style="color: #007700">= </span><span style="color: #0000BB">4</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$string </span><span style="color: #007700">= </span><span style="color: #DD0000">"This string has four words."</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$string </span><span style="color: #007700">= </span><span style="color: #0000BB">ereg_replace</span><span style="color: #007700">(</span><span style="color: #DD0000">'four'</span><span style="color: #007700">, </span><span style="color: #0000BB">$num</span><span style="color: #007700">, </span><span style="color: #0000BB">$string</span><span style="color: #007700">);<br />echo </span><span style="color: #0000BB">$string</span><span style="color: #007700">; </span><span style="color: #FF8000">/* Output: 'This string has words.' */<br /><br />/* This will work. */<br /></span><span style="color: #0000BB">$num </span><span style="color: #007700">= </span><span style="color: #DD0000">'4'</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$string </span><span style="color: #007700">= </span><span style="color: #DD0000">"This string has four words."</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$string </span><span style="color: #007700">= </span><span style="color: #0000BB">ereg_replace</span><span style="color: #007700">(</span><span style="color: #DD0000">'four'</span><span style="color: #007700">, </span><span style="color: #0000BB">$num</span><span style="color: #007700">, </span><span style="color: #0000BB">$string</span><span style="color: #007700">);<br />echo </span><span style="color: #0000BB">$string</span><span style="color: #007700">; </span><span style="color: #FF8000">/* Output: 'This string has 4 words.' */<br /></span><span style="color: #0000BB">?></span> </span> </code></div> </div> </div> </p> <p class="para"> <div class="example" id="example-4808"> <p><strong>Example #3 Replace URLs with links</strong></p> <div class="example-contents"> <div class="phpcode"><code><span style="color: #000000"> <span style="color: #0000BB"><?php<br />$text </span><span style="color: #007700">= </span><span style="color: #0000BB">ereg_replace</span><span style="color: #007700">(</span><span style="color: #DD0000">"[[:alpha:]]+://[^<>[:space:]]+[[:alnum:]/]"</span><span style="color: #007700">,<br /> </span><span style="color: #DD0000">'<a href="\\0">\\0</a>'</span><span style="color: #007700">, </span><span style="color: #0000BB">$text</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span> </span> </code></div> </div> </div> </p> </div> <div class="refsect1 notes" id="refsect1-function.ereg-replace-notes"> <h3 class="title">Notes</h3> <blockquote class="note"><p><strong class="note">Note</strong>: <p class="para">As of PHP 5.3.0, the regex extension is deprecated in favor of the <a href="book.pcre.html" class="link">PCRE extension</a>. Calling this function will issue an <strong><code>E_DEPRECATED</code></strong> notice. See <a href="reference.pcre.pattern.posix.html" class="link">the list of differences</a> for help on converting to PCRE.</p></p></blockquote> <div class="tip"><strong class="tip">Tip</strong> <p class="para"> <span class="function"><strong>ereg_replace()</strong></span> is deprecated as of PHP 5.3.0. <span class="function"><a href="function.preg-replace.html" class="function">preg_replace()</a></span> is the suggested alternative to this function. </p> </div> </div> <div class="refsect1 seealso" id="refsect1-function.ereg-replace-seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"> <span class="function"><a href="function.ereg.html" class="function" rel="rdfs-seeAlso">ereg()</a> - Regular expression match</span></li> <li class="member"> <span class="function"><a href="function.eregi.html" class="function" rel="rdfs-seeAlso">eregi()</a> - Case insensitive regular expression match</span></li> <li class="member"> <span class="function"><a href="function.eregi-replace.html" class="function" rel="rdfs-seeAlso">eregi_replace()</a> - Replace regular expression case insensitive</span></li> <li class="member"> <span class="function"><a href="function.str-replace.html" class="function" rel="rdfs-seeAlso">str_replace()</a> - Replace all occurrences of the search string with the replacement string</span></li> <li class="member"> <span class="function"><a href="function.preg-replace.html" class="function" rel="rdfs-seeAlso">preg_replace()</a> - Perform a regular expression search and replace</span></li> <li class="member"> <span class="function"><a href="function.quotemeta.html" class="function" rel="rdfs-seeAlso">quotemeta()</a> - Quote meta characters</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="ref.regex.html">POSIX Regex Functions</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.ereg.html">ereg</a></div> <div class="up"><a href="ref.regex.html">POSIX Regex Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div></body></html>