JQuery.fn.extend() method actually extends the jQuery prototype ($.fn) object to provide new methods which can be chained to JQuery. For e.g- After searching the elemnts using Jquery, I want to call my custom methods that too with chaining, in that case I will extend it.

  1. <label>
  2. <input type="checkbox" name="foo" />
  3. Foo</label>
  4. <label>
  5. <input type="checkbox" name="bar" />
  6. Bar</label>
  7. <script type="text/javascript">
  8. jQuery.fn.extend({
  9. check: function () {
  10. return this.each(function () {
  11. this.checked = true;
  12. alert('f');
  13. });
  14. },
  15. uncheck: function () {
  16. return this.each(function () {
  17. this.checked = false;
  18. });
  19. }
  20. });
  22. $("input[type='checkbox']").check();
  24. </script>

Hope this helps you.