entries/jQuery.isFunction.xml

<?xml version="1.0"?>
<entry type="method" name="jQuery.isFunction" return="boolean" deprecated="3.3" removed="4.0">
  <title>jQuery.isFunction()</title>
  <signature>
    <added>1.2</added>
    <argument name="value" type="Anything">
      <desc>The value to be tested.</desc>
    </argument>
  </signature>
  <desc>Determines if its argument is callable as a function.</desc>
  <longdesc>
    <div class="warning">
      <p>As of jQuery 3.3, <code>jQuery.isFunction()</code> has been deprecated. In most cases, its use can be replaced by <code>typeof x === "function"</code>.</p>
    </div>
    <p><strong>Note:</strong> As of jQuery 1.3, functions provided by the browser like <code>alert()</code> and DOM element methods like <code>getAttribute()</code> are not guaranteed to be detected as functions in browsers such as Internet Explorer.</p>
  </longdesc>
  <example>
    <desc>Test a few parameter examples.</desc>
    <code><![CDATA[
function stub() {}
var objs = [
  function() {},
  { x:15, y:20 },
  null,
  stub,
  "function"
];

jQuery.each( objs, function( i ) {
  var isFunc = jQuery.isFunction( objs[ i ]);
  $( "span" ).eq( i ).text( isFunc );
});
]]></code>
    <css><![CDATA[
  div {
    color: blue;
    margin: 2px;
    font-size: 14px;
  }
  span {
    color: red;
  }
]]></css>
    <html><![CDATA[
<div>jQuery.isFunction( objs[ 0 ] ) = <span></span></div>
<div>jQuery.isFunction( objs[ 1 ] ) = <span></span></div>
<div>jQuery.isFunction( objs[ 2 ] ) = <span></span></div>
<div>jQuery.isFunction( objs[ 3 ] ) = <span></span></div>
<div>jQuery.isFunction( objs[ 4 ] ) = <span></span></div>
]]></html>
  </example>
  <example>
    <desc>Finds out if the parameter is a function.</desc>
    <code><![CDATA[
$.isFunction(function() {});
]]></code>
    <results><![CDATA[
true
]]></results>
  </example>
  <category slug="utilities"/>
  <category slug="version/1.2"/>
  <category slug="deprecated/deprecated-3.3"/>
</entry>