## jQuery.fn.extend( object )Returns: Object

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

- #### version added: 1.0 jQuery.fn.extend( object )

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

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

## Example:

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

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    <!doctype html><html lang="en"><head>  <meta charset="utf-8">  <title>jQuery.fn.extend demo</title>  <style>  label {    display: block;    margin: .5em;  }  </style>  <script src="https://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: