📄 function.require.html
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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>require</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.return.html">return</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.include.html">include</a></div> <div class="up"><a href="language.control-structures.html">Control Structures</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="function.require" class="sect1"> <h2 class="title"><b>require()</b></h2> <p class="simpara"> The <b>require()</b> statement includes and evaluates the specific file. </p> <p class="simpara"> <b>require()</b> includes and evaluates a specific file. Detailed information on how this inclusion works is described in the documentation for <b>include()</b>. </p> <p class="simpara"> <b>require()</b> and <b>include()</b> are identical in every way except how they handle failure. They both produce a <a href="errorfunc.constants.html#errorfunc.constants.errorlevels.e-warning" class="link">Warning</a>, but <b>require()</b> results in a <a href="errorfunc.constants.html#errorfunc.constants.errorlevels.e-error" class="link"> Fatal Error</a>. In other words, don't hesitate to use <b>require()</b> if you want a missing file to halt processing of the page. <b>include()</b> does not behave this way, the script will continue regardless. Be sure to have an appropriate <a href="ini.core.html#ini.include-path" class="link">include_path</a> setting as well. </p> <p class="para"> <div class="example"> <p><b>Example #1 Basic <b>require()</b> examples</b></p> <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br /><br /></span><span style="color: #007700">require </span><span style="color: #DD0000">'prepend.php'</span><span style="color: #007700">;<br /><br />require </span><span style="color: #0000BB">$somefile</span><span style="color: #007700">;<br /><br />require (</span><span style="color: #DD0000">'somefile.txt'</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">?></span></span></code></div> </div> </div> </p> <p class="simpara"> See the <b>include()</b> documentation for more examples. </p> <p class="para"> <blockquote><p><b class="note">Note</b>: <span class="simpara"> Prior to PHP 4.0.2, the following applies: <b>require()</b> will always attempt to read the target file, even if the line it's on never executes. The conditional statement won't affect <b>require()</b>. However, if the line on which the <b>require()</b> occurs is not executed, neither will any of the code in the target file be executed. Similarly, looping structures do not affect the behaviour of <b>require()</b>. Although the code contained in the target file is still subject to the loop, the <b>require()</b> itself happens only once. </span> </p></blockquote> </p> <blockquote><p><b class="note">Note</b>: <span class="simpara">Because this is a language construct and not a function, it cannot be called using <a href="functions.variable-functions.html" class="link">variable functions</a></span></p></blockquote> <div class="warning"><b class="warning">Warning</b><p class="para">Windows versions of PHPprior to PHP 4.3.0 do not support access of remote files via this function,even if <a href="filesystem.configuration.html#ini.allow-url-fopen" class="link">allow_url_fopen</a> is enabled.</p></div> <p class="simpara"> See also <b>include()</b>, <b>require_once()</b>, <b>include_once()</b>, <a href="function.get-included-files.html" class="function">get_included_files()</a>, <a href="function.eval.html" class="function">eval()</a>, <a href="function.file.html" class="function">file()</a>, <a href="function.readfile.html" class="function">readfile()</a>, <a href="function.virtual.html" class="function">virtual()</a> and <a href="ini.core.html#ini.include-path" class="link">include_path</a>. </p> </div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.return.html">return</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.include.html">include</a></div> <div class="up"><a href="language.control-structures.html">Control Structures</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div></body></html>⌨️ 快捷键说明
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