<!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>Predefined Constants</title> </head> <body><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="array.resources.html">Resource Types</a></div> <div class="next" style="text-align: right; float: right;"><a href="array.sorting.html">Sorting Arrays</a></div> <div class="up"><a href="book.array.html">Arrays</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div><hr /><div id="array.constants" class="appendix"> <h1>Predefined Constants</h1> <p class="simpara"> The constants below are always available as part of the PHP core. </p> <p class="para"> <dl> <dt id="constant.case-lower"> <strong><code>CASE_LOWER</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> <strong><code>CASE_LOWER</code></strong> is used with <span class="function"><a href="function.array-change-key-case.html" class="function">array_change_key_case()</a></span> and is used to convert array keys to lower case. This is also the default case for <span class="function"><a href="function.array-change-key-case.html" class="function">array_change_key_case()</a></span>. </span> </dd> <dt id="constant.case-upper"> <strong><code>CASE_UPPER</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> <strong><code>CASE_UPPER</code></strong> is used with <span class="function"><a href="function.array-change-key-case.html" class="function">array_change_key_case()</a></span> and is used to convert array keys to upper case. </span> </dd> </dl> </p> <p class="para"> Sorting order flags: <dl> <dt id="constant.sort-asc"> <strong><code>SORT_ASC</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> <strong><code>SORT_ASC</code></strong> is used with <span class="function"><a href="function.array-multisort.html" class="function">array_multisort()</a></span> to sort in ascending order. </span> </dd> <dt id="constant.sort-desc"> <strong><code>SORT_DESC</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> <strong><code>SORT_DESC</code></strong> is used with <span class="function"><a href="function.array-multisort.html" class="function">array_multisort()</a></span> to sort in descending order. </span> </dd> </dl> </p> <p class="para"> Sorting type flags: used by various sort functions <dl> <dt id="constant.sort-regular"> <strong><code>SORT_REGULAR</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> <strong><code>SORT_REGULAR</code></strong> is used to compare items normally. </span> </dd> <dt id="constant.sort-numeric"> <strong><code>SORT_NUMERIC</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> <strong><code>SORT_NUMERIC</code></strong> is used to compare items numerically. </span> </dd> <dt id="constant.sort-string"> <strong><code>SORT_STRING</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> <strong><code>SORT_STRING</code></strong> is used to compare items as strings. </span> </dd> <dt id="constant.sort-locale-string"> <strong><code>SORT_LOCALE_STRING</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> <strong><code>SORT_LOCALE_STRING</code></strong> is used to compare items as strings, based on the current locale. Added in PHP 5.0.2. </span> </dd> <dt id="constant.sort-natural"> <strong><code>SORT_NATURAL</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> <strong><code>SORT_NATURAL</code></strong> is used to compare items as strings using "natural ordering" like <span class="function"><a href="function.natsort.html" class="function">natsort()</a></span>. Added in PHP 5.4.0. </span> </dd> <dt id="constant.sort-flag-case"> <strong><code>SORT_FLAG_CASE</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> <strong><code>SORT_FLAG_CASE</code></strong> can be combined (bitwise OR) with <strong><code>SORT_STRING</code></strong> or <strong><code>SORT_NATURAL</code></strong> to sort strings case-insensitively. Added in PHP 5.4.0. </span> </dd> </dl> </p> <p class="para"> Filter flags: <dl> <dt id="constant.array-filter-use-key"> <strong><code>ARRAY_FILTER_USE_KEY</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> <strong><code>ARRAY_FILTER_USE_KEY</code></strong> is used with <span class="function"><a href="function.array-filter.html" class="function">array_filter()</a></span> to pass each key as the first argument to the given callback function. Added in PHP 5.6.0. </span> </dd> <dt id="constant.array-filter-use-both"> <strong><code>ARRAY_FILTER_USE_BOTH</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> <strong><code>ARRAY_FILTER_USE_BOTH</code></strong> is used with <span class="function"><a href="function.array-filter.html" class="function">array_filter()</a></span> to pass both value and key to the given callback function. Added in PHP 5.6.0. </span> </dd> </dl> </p> <dl> <dt id="constant.count-normal"> <strong><code>COUNT_NORMAL</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> </span> </dd> <dt id="constant.count-recursive"> <strong><code>COUNT_RECURSIVE</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> </span> </dd> <dt id="constant.extr-overwrite"> <strong><code>EXTR_OVERWRITE</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> </span> </dd> <dt id="constant.extr-skip"> <strong><code>EXTR_SKIP</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> </span> </dd> <dt id="constant.extr-prefix-same"> <strong><code>EXTR_PREFIX_SAME</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> </span> </dd> <dt id="constant.extr-prefix-all"> <strong><code>EXTR_PREFIX_ALL</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> </span> </dd> <dt id="constant.extr-prefix-invalid"> <strong><code>EXTR_PREFIX_INVALID</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> </span> </dd> <dt id="constant.extr-prefix-if-exists"> <strong><code>EXTR_PREFIX_IF_EXISTS</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> </span> </dd> <dt id="constant.extr-if-exists"> <strong><code>EXTR_IF_EXISTS</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> </span> </dd> <dt id="constant.extr-refs"> <strong><code>EXTR_REFS</code></strong> (<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span>) </dt> <dd> <span class="simpara"> </span> </dd> </dl> </div> <hr /><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="array.resources.html">Resource Types</a></div> <div class="next" style="text-align: right; float: right;"><a href="array.sorting.html">Sorting Arrays</a></div> <div class="up"><a href="book.array.html">Arrays</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div></body></html>