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href="https://pub.dev" target="_blank" rel="noopener">Package site</a></li></ul></li></ul></div></div><main id="page-content"><article><div class="content"><nav id="subnav"><ul><li class="previous"><a href="/language/extension-types">&lang;  Extension types</a></li><li class="next"><a href="/language/class-modifiers">Class modifiers  &rang;</a></li></ul></nav><div id="site-content-title"><h1>Callable objects</h1></div> <?code-excerpt replace="/ *\/\/\s+ignore_for_file:[^\n]+\n//g; /(^|\n) *\/\/\s+ignore: (stable|beta|dev)[^\n]+\n/$1/g; /(\n[^\n]+) *\/\/\s+ignore: (stable|beta|dev)[^\n]+\n/$1\n/g; /. • (lib|test)\/\w+\.dart:\d+:\d+//g"?> <p>To allow an instance of your Dart class to be called like a function, implement the <code>call()</code> method.</p><p>The <code>call()</code> method allows an instance of any class that defines it to emulate a function. This method supports the same functionality as normal <a href="/language/functions">functions</a> such as parameters and return types.</p><p>In the following example, the <code>WannabeFunction</code> class defines a <code>call()</code> function that takes three strings and concatenates them, separating each with a space, and appending an exclamation. Click <strong>Run</strong> to execute the code.</p> <?code-excerpt "misc/lib/language_tour/callable_objects.dart"?> <pre><code data-dartpad="true" data-embed="true" data-theme="light" title="Runnable Dart sample" data-run="false">class WannabeFunction { String call(String a, String b, String c) => '$a $b $c!'; } var wf = WannabeFunction(); var out = wf('Hi', 'there,', 'gang'); void main() => print(out); </code></pre><nav id="subnav"><ul><li class="previous"><a href="/language/extension-types">&lang;  Extension types</a></li><li class="next"><a href="/language/class-modifiers">Class modifiers  &rang;</a></li></ul></nav><p id="page-github-links"><span>Unless stated otherwise, the documentation on this site reflects Dart 3.5.4. Page last updated on 2024-05-30.</span> <a href="https://github.com/dart-lang/site-www/tree/main/src/content/language/callable-objects.md" target="_blank" rel="noopener">View source</a> <span>or </span><a href="https://github.com/dart-lang/site-www/issues/new?template=1_page_issue.yml&page-url=https://dart.dev/language/callable-objects/&page-source=https://github.com/dart-lang/site-www/tree/main/src/content/language/callable-objects.md" title="Report an issue with this page" target="_blank" rel="noopener">report an issue</a>.</p></div></article></main><footer id="page-footer"><div class="footer-section footer-main"><a href="/" class="brand" title="Dart"><img src="/assets/img/logo/logo-white-text.svg" alt="Dart" width="164"></a><div class="footer-social-links"><a href="https://medium.com/dartlang" target="_blank" rel="noopener" title="Medium blog"><svg><use href="/assets/img/social/medium.svg#medium"></use></svg> </a><a href="https://github.com/dart-lang" target="_blank" rel="noopener" title="GitHub"><svg><use href="/assets/img/social/github.svg#github"></use></svg> </a><a href="https://twitter.com/dart_lang" target="_blank" rel="noopener" title="X (Twitter)"><svg><use href="/assets/img/social/x.svg#x"></use></svg></a></div></div><div class="footer-section footer-tray"><div class="footer-licenses">Except as otherwise noted, this site is licensed under a <a href="https://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution 4.0 International License</a>, and code samples are licensed under the <a href="https://opensource.org/licenses/BSD-3-Clause">3-Clause BSD License</a>.</div><div class="footer-utility-links"><ul><li><a href="/terms" title="Terms of use">Terms</a></li><li><a href="https://policies.google.com/privacy" target="_blank" rel="noopener" title="Privacy policy">Privacy</a></li><li><a href="/security" title="Security philosophy and practices">Security</a></li></ul></div></div></footer></body></html>