JavaScript Tutorial

jQuery.inArray()

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>jQuery.inArray demo</title>
  <style>
  div {
    color: blue;
  }
  span {
    color: red;
  }
  </style>
  <script src="https://code.jquery.com/jquery-1.10.2.js"></script>
</head>
<body>
    <div>"John" found at <span></span></div>
    <div>4 found at <span></span></div>
    <div>"Karl" not found, so <span></span></div>
    <div>"Pete" is in the array, but not at or after index 2, so <span></span></div>
    <script>
        var arr = [ 4, "Pete", 8, "John" ];
        var $spans = $( "span" );
        $spans.eq( 0 ).text( jQuery.inArray( "John", arr ) );
        $spans.eq( 1 ).text( jQuery.inArray( 4, arr ) );
        $spans.eq( 2 ).text( jQuery.inArray( "Karl", arr ) );
        $spans.eq( 3 ).text( jQuery.inArray( "Pete", arr, 2 ) );
    </script>
</body>
</html>