CINXE.COM
delete - Perldoc Browser
<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>delete - Perldoc Browser</title> <link rel="search" href="/opensearch.xml" type="application/opensearchdescription+xml" title="Perldoc Browser"> <link rel="canonical" href="https://perldoc.perl.org/functions/delete"> <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" integrity="sha384-JcKb8q3iqJ61gNV9KGb8thSsNjpSL0n8PARn9HuZOnIxN0hoP+VmmDGMN5t9UJ0Z" crossorigin="anonymous"> <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.5.0/styles/stackoverflow-light.min.css" integrity="sha512-cG1IdFxqipi3gqLmksLtuk13C+hBa57a6zpWxMeoY3Q9O6ooFxq50DayCdm0QrDgZjMUn23z/0PMZlgft7Yp5Q==" crossorigin="anonymous" /> <style> body { background: #f4f4f5; color: #020202; } .navbar-dark { background-image: -webkit-linear-gradient(top, #005f85 0, #002e49 100%); background-image: -o-linear-gradient(top, #005f85 0, #002e49 100%); background-image: linear-gradient(to bottom, #005f85 0, #002e49 100%); filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#ff005f85', endColorstr='#ff002e49', GradientType=0); background-repeat: repeat-x; } .navbar-dark .navbar-nav .nav-link, .navbar-dark .navbar-nav .nav-link:focus { color: #fff } .navbar-dark .navbar-nav .nav-link:hover { color: #ffef68 } #wrapperlicious { margin: 0 auto; font: 0.9em 'Helvetica Neue', Helvetica, sans-serif; font-weight: normal; line-height: 1.5em; margin: 0; padding: 0; } #wrapperlicious h1 { font-size: 1.5em } #wrapperlicious h2 { font-size: 1.3em } #wrapperlicious h3 { font-size: 1.1em } #wrapperlicious h4 { font-size: 0.9em } #wrapperlicious h1, #wrapperlicious h2, #wrapperlicious h3, #wrapperlicious h4, #wrapperlicious dt { color: #020202; margin-top: 1em; margin-bottom: 1em; position: relative; font-weight: bold; } #wrapperlicious a { color: inherit; text-decoration: underline } #wrapperlicious #toc { text-decoration: none } #wrapperlicious a:hover { color: #2a2a2a } #wrapperlicious a img { border: 0 } #wrapperlicious :not(pre) > code { color: inherit; background-color: rgba(0, 0, 0, 0.04); border-radius: 3px; font: 0.9em Consolas, Menlo, Monaco, monospace; padding: 0.3em; } #wrapperlicious dd { margin: 0; margin-left: 2em; } #wrapperlicious dt { color: #2a2a2a; font-weight: bold; margin-left: 0.9em; } #wrapperlicious p { margin-bottom: 1em; margin-top: 1em; } #wrapperlicious li > p { margin-bottom: 0; margin-top: 0; } #wrapperlicious pre { border: 1px solid #c1c1c1; border-radius: 3px; font: 100% Consolas, Menlo, Monaco, monospace; margin-bottom: 1em; margin-top: 1em; } #wrapperlicious pre > code { display: block; background-color: #f6f6f6; font: 0.9em Consolas, Menlo, Monaco, monospace; line-height: 1.5em; text-align: left; white-space: pre; padding: 1em; } #wrapperlicious dl, #wrapperlicious ol, #wrapperlicious ul { margin-bottom: 1em; margin-top: 1em; } #wrapperlicious ul { list-style-type: square; } #wrapperlicious ul ul { margin-bottom: 0px; margin-top: 0px; } #footer { font-size: 0.8em; padding-top: 0.5em; text-align: center; } #more { display: inline; font-size: 0.8em; } #perldocdiv { background-color: #fff; border: 1px solid #c1c1c1; border-bottom-left-radius: 5px; border-bottom-right-radius: 5px; margin-left: auto; margin-right: auto; padding: 3em; padding-top: 1em; max-width: 960px; } #moduleversion { float: right } #wrapperlicious .leading-notice { font-style: italic; padding-left: 1em; margin-top: 1em; margin-bottom: 1em; } #wrapperlicious .permalink { display: none; left: -0.75em; position: absolute; padding-right: 0.25em; text-decoration: none; } #wrapperlicious h1:hover .permalink, #wrapperlicious h2:hover .permalink, #wrapperlicious h3:hover .permalink, #wrapperlicious h4:hover .permalink, #wrapperlicious dt:hover .permalink { display: block; } </style> <!-- Global site tag (gtag.js) - Google Analytics --> <script async src="https://www.googletagmanager.com/gtag/js?id=G-KVNWBNT5FB"></script> <script> window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'G-KVNWBNT5FB'); gtag('config', 'UA-50555-3'); </script> </head> <body> <nav class="navbar navbar-expand-md navbar-dark bg-dark justify-content-between"> <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon"></span> </button> <a class="navbar-brand" href="/"><img src="/images/perl_camel_30.png" width="30" height="30" class="d-inline-block align-top" alt="Perl Camel Logo"> Perldoc Browser</a> <div class="collapse navbar-collapse" id="navbarNav"> <ul class="navbar-nav mr-auto"> <li class="nav-item dropdown text-nowrap"> <a class="nav-link dropdown-toggle" href="#" id="dropdownlink-stable" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">5.14.2</a> <div class="dropdown-menu" aria-labelledby="dropdownlink-stable"> <a class="dropdown-item" href="/functions/delete">Latest</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.40.1/functions/delete">5.40.1</a> <a class="dropdown-item" href="/5.40.0/functions/delete">5.40.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.38.3/functions/delete">5.38.3</a> <a class="dropdown-item" href="/5.38.2/functions/delete">5.38.2</a> <a class="dropdown-item" href="/5.38.1/functions/delete">5.38.1</a> <a class="dropdown-item" href="/5.38.0/functions/delete">5.38.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.36.3/functions/delete">5.36.3</a> <a class="dropdown-item" href="/5.36.2/functions/delete">5.36.2</a> <a class="dropdown-item" href="/5.36.1/functions/delete">5.36.1</a> <a class="dropdown-item" href="/5.36.0/functions/delete">5.36.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.34.3/functions/delete">5.34.3</a> <a class="dropdown-item" href="/5.34.2/functions/delete">5.34.2</a> <a class="dropdown-item" href="/5.34.1/functions/delete">5.34.1</a> <a class="dropdown-item" href="/5.34.0/functions/delete">5.34.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.32.1/functions/delete">5.32.1</a> <a class="dropdown-item" href="/5.32.0/functions/delete">5.32.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.30.3/functions/delete">5.30.3</a> <a class="dropdown-item" href="/5.30.2/functions/delete">5.30.2</a> <a class="dropdown-item" href="/5.30.1/functions/delete">5.30.1</a> <a class="dropdown-item" href="/5.30.0/functions/delete">5.30.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.28.3/functions/delete">5.28.3</a> <a class="dropdown-item" href="/5.28.2/functions/delete">5.28.2</a> <a class="dropdown-item" href="/5.28.1/functions/delete">5.28.1</a> <a class="dropdown-item" href="/5.28.0/functions/delete">5.28.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.26.3/functions/delete">5.26.3</a> <a class="dropdown-item" href="/5.26.2/functions/delete">5.26.2</a> <a class="dropdown-item" href="/5.26.1/functions/delete">5.26.1</a> <a class="dropdown-item" href="/5.26.0/functions/delete">5.26.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.24.4/functions/delete">5.24.4</a> <a class="dropdown-item" href="/5.24.3/functions/delete">5.24.3</a> <a class="dropdown-item" href="/5.24.2/functions/delete">5.24.2</a> <a class="dropdown-item" href="/5.24.1/functions/delete">5.24.1</a> <a class="dropdown-item" href="/5.24.0/functions/delete">5.24.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.22.4/functions/delete">5.22.4</a> <a class="dropdown-item" href="/5.22.3/functions/delete">5.22.3</a> <a class="dropdown-item" href="/5.22.2/functions/delete">5.22.2</a> <a class="dropdown-item" href="/5.22.1/functions/delete">5.22.1</a> <a class="dropdown-item" href="/5.22.0/functions/delete">5.22.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.20.3/functions/delete">5.20.3</a> <a class="dropdown-item" href="/5.20.2/functions/delete">5.20.2</a> <a class="dropdown-item" href="/5.20.1/functions/delete">5.20.1</a> <a class="dropdown-item" href="/5.20.0/functions/delete">5.20.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.18.4/functions/delete">5.18.4</a> <a class="dropdown-item" href="/5.18.3/functions/delete">5.18.3</a> <a class="dropdown-item" href="/5.18.2/functions/delete">5.18.2</a> <a class="dropdown-item" href="/5.18.1/functions/delete">5.18.1</a> <a class="dropdown-item" href="/5.18.0/functions/delete">5.18.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.16.3/functions/delete">5.16.3</a> <a class="dropdown-item" href="/5.16.2/functions/delete">5.16.2</a> <a class="dropdown-item" href="/5.16.1/functions/delete">5.16.1</a> <a class="dropdown-item" href="/5.16.0/functions/delete">5.16.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.14.4/functions/delete">5.14.4</a> <a class="dropdown-item" href="/5.14.3/functions/delete">5.14.3</a> <a class="dropdown-item active" href="/5.14.2/functions/delete">5.14.2</a> <a class="dropdown-item" href="/5.14.1/functions/delete">5.14.1</a> <a class="dropdown-item" href="/5.14.0/functions/delete">5.14.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.12.5/functions/delete">5.12.5</a> <a class="dropdown-item" href="/5.12.4/functions/delete">5.12.4</a> <a class="dropdown-item" href="/5.12.3/functions/delete">5.12.3</a> <a class="dropdown-item" href="/5.12.2/functions/delete">5.12.2</a> <a class="dropdown-item" href="/5.12.1/functions/delete">5.12.1</a> <a class="dropdown-item" href="/5.12.0/functions/delete">5.12.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.10.1/functions/delete">5.10.1</a> <a class="dropdown-item" href="/5.10.0/functions/delete">5.10.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.8.9/functions/delete">5.8.9</a> <a class="dropdown-item" href="/5.8.8/functions/delete">5.8.8</a> <a class="dropdown-item" href="/5.8.7/functions/delete">5.8.7</a> <a class="dropdown-item" href="/5.8.6/functions/delete">5.8.6</a> <a class="dropdown-item" href="/5.8.5/functions/delete">5.8.5</a> <a class="dropdown-item" href="/5.8.4/functions/delete">5.8.4</a> <a class="dropdown-item" href="/5.8.3/functions/delete">5.8.3</a> <a class="dropdown-item" href="/5.8.2/functions/delete">5.8.2</a> <a class="dropdown-item" href="/5.8.1/functions/delete">5.8.1</a> <a class="dropdown-item" href="/5.8.0/functions/delete">5.8.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.6.2/functions/delete">5.6.2</a> <a class="dropdown-item" href="/5.6.1/functions/delete">5.6.1</a> <a class="dropdown-item" href="/5.6.0/functions/delete">5.6.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.005_04/functions/delete">5.005_04</a> <a class="dropdown-item" href="/5.005_03/functions/delete">5.005_03</a> <a class="dropdown-item" href="/5.005_02/functions/delete">5.005_02</a> <a class="dropdown-item" href="/5.005_01/functions/delete">5.005_01</a> <a class="dropdown-item" href="/5.005/functions/delete">5.005</a> </div> </li> <li class="nav-item dropdown text-nowrap"> <a class="nav-link dropdown-toggle" href="#" id="dropdownlink-dev" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Dev</a> <div class="dropdown-menu" aria-labelledby="dropdownlink-dev"> <a class="dropdown-item" href="/blead/functions/delete">blead</a> <a class="dropdown-item" href="/5.41.10/functions/delete">5.41.10</a> <a class="dropdown-item" href="/5.41.9/functions/delete">5.41.9</a> <a class="dropdown-item" href="/5.41.8/functions/delete">5.41.8</a> <a class="dropdown-item" href="/5.41.7/functions/delete">5.41.7</a> <a class="dropdown-item" href="/5.41.6/functions/delete">5.41.6</a> <a class="dropdown-item" href="/5.41.5/functions/delete">5.41.5</a> <a class="dropdown-item" href="/5.41.4/functions/delete">5.41.4</a> <a class="dropdown-item" href="/5.41.3/functions/delete">5.41.3</a> <a class="dropdown-item" href="/5.41.2/functions/delete">5.41.2</a> <a class="dropdown-item" href="/5.41.1/functions/delete">5.41.1</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.40.1-RC1/functions/delete">5.40.1-RC1</a> <a class="dropdown-item" href="/5.40.0-RC2/functions/delete">5.40.0-RC2</a> <a class="dropdown-item" href="/5.40.0-RC1/functions/delete">5.40.0-RC1</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.39.10/functions/delete">5.39.10</a> <a class="dropdown-item" href="/5.39.9/functions/delete">5.39.9</a> <a class="dropdown-item" href="/5.39.8/functions/delete">5.39.8</a> <a class="dropdown-item" href="/5.39.7/functions/delete">5.39.7</a> <a class="dropdown-item" href="/5.39.6/functions/delete">5.39.6</a> <a class="dropdown-item" href="/5.39.5/functions/delete">5.39.5</a> <a class="dropdown-item" href="/5.39.4/functions/delete">5.39.4</a> <a class="dropdown-item" href="/5.39.3/functions/delete">5.39.3</a> <a class="dropdown-item" href="/5.39.2/functions/delete">5.39.2</a> <a class="dropdown-item" href="/5.39.1/functions/delete">5.39.1</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.38.3-RC1/functions/delete">5.38.3-RC1</a> </div> </li> <li class="nav-item dropdown text-nowrap"> <a class="nav-link dropdown-toggle" href="#" id="dropdownlink-nav" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Documentation</a> <div class="dropdown-menu" aria-labelledby="dropdownlink-nav"> <a class="dropdown-item" href="/5.14.2/perl">Perl</a> <a class="dropdown-item" href="/5.14.2/perlintro">Intro</a> <a class="dropdown-item" href="/5.14.2/perl#Tutorials">Tutorials</a> <a class="dropdown-item" href="/5.14.2/perlfaq">FAQs</a> <a class="dropdown-item" href="/5.14.2/perl#Reference-Manual">Reference</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.14.2/perlop">Operators</a> <a class="dropdown-item" href="/5.14.2/functions">Functions</a> <a class="dropdown-item" href="/5.14.2/variables">Variables</a> <a class="dropdown-item" href="/5.14.2/modules">Modules</a> <a class="dropdown-item" href="/5.14.2/perlutil">Utilities</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.14.2/perldelta">Release Notes</a> <a class="dropdown-item" href="/5.14.2/perlcommunity">Community</a> <a class="dropdown-item" href="/5.14.2/perlhist">History</a> </div> </li> </ul> <ul class="navbar-nav"> <script> function set_expand (expand) { var perldocdiv = document.getElementById('perldocdiv'); var width = window.getComputedStyle(perldocdiv).getPropertyValue('max-width'); var expanded = (width == '' || width == 'none') ? true : false; if (expand === null) { expand = !expanded; } if ((expand && !expanded) || (!expand && expanded)) { perldocdiv.style.setProperty('max-width', expand ? 'none' : '960px'); var button_classlist = document.getElementById('content-expand-button').classList; if (expand) { button_classlist.add('btn-light'); button_classlist.remove('btn-outline-light'); } else { button_classlist.add('btn-outline-light'); button_classlist.remove('btn-light'); } } return expand; } function toggle_expand () { var expand = set_expand(null); document.cookie = 'perldoc_expand=' + (expand ? 1 : 0) + '; path=/; expires=Tue, 19 Jan 2038 03:14:07 UTC'; } function read_expand () { return document.cookie.split(';').some(function (item) { return item.indexOf('perldoc_expand=1') >= 0 }); } if (document.readyState === 'loading') { document.addEventListener('DOMContentLoaded', function () { if (read_expand()) { set_expand(true); } }); } else if (read_expand()) { set_expand(true); } </script> <button id="content-expand-button" type="button" class="btn btn-outline-light d-none d-lg-inline-block mr-4" onclick="toggle_expand()">Expand</button> </ul> <form class="form-inline" method="get" action="/5.14.2/search"> <input class="form-control mr-3" type="search" name="q" placeholder="Search" aria-label="Search" value=""> </form> </div> </nav> <div id="wrapperlicious" class="container-fluid"> <div id="perldocdiv"> <div id="links"> <a href="/5.14.2/functions">functions</a> / <a href="/5.14.2/functions/delete">delete</a> <div id="more"> (<a href="/5.14.2/functions/delete.txt">source</a>, <a href="https://metacpan.org/pod/perlfunc#delete-EXPR">CPAN</a>) </div> </div> <div class="leading-notice"> You are viewing the version of this documentation from Perl 5.14.2. <a href="/functions/delete">View the latest version</a> </div> <dl> <dt id="delete-EXPR"><a class="permalink" href="#delete-EXPR">#</a><a id="delete"></a>delete EXPR </dt> <dd> <p>Given an expression that specifies an element or slice of a hash, <code>delete</code> deletes the specified elements from that hash so that exists() on that element no longer returns true. Setting a hash element to the undefined value does not remove its key, but deleting it does; see <a href="/5.14.2/functions/exists">"exists"</a>.</p> <p>In list context, returns the value or values deleted, or the last such element in scalar context. The return list's length always matches that of the argument list: deleting non-existent elements returns the undefined value in their corresponding positions.</p> <p>delete() may also be used on arrays and array slices, but its behavior is less straightforward. Although exists() will return false for deleted entries, deleting array elements never changes indices of existing values; use shift() or splice() for that. However, if all deleted elements fall at the end of an array, the array's size shrinks to the position of the highest element that still tests true for exists(), or to 0 if none do.</p> <p><b>WARNING:</b> Calling delete on array values is deprecated and likely to be removed in a future version of Perl.</p> <p>Deleting from <code>%ENV</code> modifies the environment. Deleting from a hash tied to a DBM file deletes the entry from the DBM file. Deleting from a <code>tied</code> hash or array may not necessarily return anything; it depends on the implementation of the <code>tied</code> package's DELETE method, which may do whatever it pleases.</p> <p>The <code>delete local EXPR</code> construct localizes the deletion to the current block at run time. Until the block exits, elements locally deleted temporarily no longer exist. See <a href="/5.14.2/perlsub#Localized-deletion-of-elements-of-composite-types">"Localized deletion of elements of composite types" in perlsub</a>.</p> <pre><code>%hash = (foo => 11, bar => 22, baz => 33); $scalar = delete $hash{foo}; # $scalar is 11 $scalar = delete @hash{qw(foo bar)}; # $scalar is 22 @array = delete @hash{qw(foo bar baz)}; # @array is (undef,undef,33)</code></pre> <p>The following (inefficiently) deletes all the values of %HASH and @ARRAY:</p> <pre><code>foreach $key (keys %HASH) { delete $HASH{$key}; } foreach $index (0 .. $#ARRAY) { delete $ARRAY[$index]; }</code></pre> <p>And so do these:</p> <pre><code>delete @HASH{keys %HASH}; delete @ARRAY[0 .. $#ARRAY];</code></pre> <p>But both are slower than assigning the empty list or undefining %HASH or @ARRAY, which is the customary way to empty out an aggregate:</p> <pre><code>%HASH = (); # completely empty %HASH undef %HASH; # forget %HASH ever existed @ARRAY = (); # completely empty @ARRAY undef @ARRAY; # forget @ARRAY ever existed</code></pre> <p>The EXPR can be arbitrarily complicated provided its final operation is an element or slice of an aggregate:</p> <pre><code>delete $ref->[$x][$y]{$key}; delete @{$ref->[$x][$y]}{$key1, $key2, @morekeys}; delete $ref->[$x][$y][$index]; delete @{$ref->[$x][$y]}[$index1, $index2, @moreindices];</code></pre> </dd> </dl> </div> <div id="footer"> <p>Perldoc Browser is maintained by Dan Book (<a href="https://metacpan.org/author/DBOOK">DBOOK</a>). Please contact him via the <a href="https://github.com/Grinnz/perldoc-browser/issues">GitHub issue tracker</a> or <a href="mailto:dbook@cpan.org">email</a> regarding any issues with the site itself, search, or rendering of documentation.</p> <p>The Perl documentation is maintained by the Perl 5 Porters in the development of Perl. Please contact them via the <a href="https://github.com/Perl/perl5/issues">Perl issue tracker</a>, the <a href="https://lists.perl.org/list/perl5-porters.html">mailing list</a>, or <a href="https://kiwiirc.com/client/irc.perl.org/p5p">IRC</a> to report any issues with the contents or format of the documentation.</p> </div> </div> <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.slim.min.js" integrity="sha512-/DXTXr6nQodMUiq+IUJYCt2PPOUjrHJ9wFrqpJ3XkgPNOZVfMok7cRw6CSxyCQxXn6ozlESsSh1/sMCTF1rL/g==" crossorigin="anonymous"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.1/umd/popper.min.js" integrity="sha512-ubuT8Z88WxezgSqf3RLuNi5lmjstiJcyezx34yIU2gAHonIi27Na7atqzUZCOoY4CExaoFumzOsFQ2Ch+I/HCw==" crossorigin="anonymous"></script> <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js" integrity="sha384-B4gt1jrGC7Jh4AgTPSdUtOBvfO8shuf57BaghqFfPlYxofvL8/KUEfYiJOMMV+rV" crossorigin="anonymous"></script> <script src="/js/highlight.pack.js"></script> <script>hljs.highlightAll();</script> </body> </html>