jQuery.fn.extend()

jQuery.fn.extend ( object ) Returns: Objectversion added: 1.0

  • object
    Type: Object
    An object to merge onto the jQuery prototype.

Description: Merge the contents of an object onto the jQuery prototype to provide new jQuery instance methods.

The jQuery.fn.extend() method extends the jQuery prototype ($.fn) object to provide new methods that can be chained to the jQuery() function.

Examples:

Example: Add two methods to the jQuery prototype ($.fn) object and then use one of them. 

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>css demo</title>

  <style>

  label {
    display: block;
    margin: .5em;
  }

  </style>

  <script src="//code.jquery.com/jquery-1.10.2.js"></script>
</head>
<body>
  

<label><input type="checkbox" name="foo"> Foo</label>
<label><input type="checkbox" name="bar"> Bar</label>

<script>

jQuery.fn.extend({
  check: function() {
    return this.each(function() {
      this.checked = true;
    });
  },
  uncheck: function() {
    return this.each(function() {
      this.checked = false;
    });
  }
});

// Use the newly created .check() method
$( "input[type='checkbox']" ).check();

</script>

  
</body>
</html>

Demo: