jQuery filter Array Method

I really enjoyed Josh Clanton’s article Filtering Arrays with Array.filter on using the JavaScript filter method(). As he points out,

Because the filter method is part of the ECMAScript 5 specification, it isn’t available in older browsers like IE8.

Josh then lists a couple of options to bring this functionality into older browsers (i.e. IE < 9) using a shim or JavaScript library. He does not list a solution for the jQuery library.  After a little research I realized the jQuery method grep provides this same functionality.

While I’m not a huge fan of the method name grep for this functionality, I’m pleased it is included in jQuery (and I understand the method filter was already being used).

// subsetArray is populated by elements of
// array where the callback function returns true
var subsetArray = jQuery.grep(
  array,
  function(elementOfArray, indexInArray)
  [, invert ]
);

Example

var origArray = [
  'apple',
  'banana',
  'boat',
  'cat',
  'cow'
];

var bArrary = jQuery.grep(
  origArray,
  function(el) {
    // return true when first
    // character is 'b'
    return 'b'=== el.charAt(0)
  }
);

// bArray =
// ["banana", "boat"]

photo credit: Pandiyan via photopin cc

Sal Ferrarello (@salcode)

Sal is a PHP and JavaScript developer with a focus on the WordPress platform. He is a conference speaker with a background including Piano Player, Radio DJ, Magician/Juggler, Beach Photographer, and High School Math Teacher. Sal can be found professionally at WebDevStudios, where he works as a principal engineer.