# callbacks.add()

## callbacks.add ( callbacks ) Returns: Callbacks version added: 1.7

- callbacks
  Type:
  A function, or array of functions, that are to be added to the callback list.

Description: Add a callback or a collection of callbacks to a callback list.

This method returns the Callbacks object onto which it is attached (`this`).

## Examples:

#### Example: Use callbacks.add() to add new callbacks to a callback list:

    // A sample logging function to be added to a callbacks list
    var foo = function( value ) {
      console.log( "foo: " + value );
    };

    // Another function to also be added to the list
    var bar = function( value ) {
      console.log( "bar: " + value );
    };

    var callbacks = $.Callbacks();

    // Add the function "foo" to the list
    callbacks.add( foo );

    // Fire the items on the list
    callbacks.fire( "hello" );
    // Outputs: "foo: hello"

    // Add the function "bar" to the list
    callbacks.add( bar );

    // Fire the items on the list again
    callbacks.fire( "world" );

    // Outputs:
    // "foo: world"
    // "bar: world"