# jQuery.speed

所属分类：特效 > 自定义 英文文档：jQuery.speed

## jQuery.speed( [duration ] [, settings ] )Returns: PlainObject

Description: Creates an object containing a set of properties ready to be used in the definition of custom animations.

- #### version added: 1.0 jQuery.speed( [duration ] [, settings ] )

  - duration (default: `400`)
    Type: Number or String
    A string or number determining how long the animation will run.
  - settings
    Type: PlainObject
    - easing (default: `swing`)
      Type: String
      A string indicating which easing function to use for the transition.
    - complete
      Type: Function()
      A function to call once the animation is complete.

- #### version added: 1.1 jQuery.speed( [duration ] [, easing ] [, complete ] )

  - duration (default: `400`)
    Type: Number or String
    A string or number determining how long the animation will run.
  - easing (default: `swing`)
    Type: String
    A string indicating which easing function to use for the transition.
  - complete
    Type: Function()
    A function to call once the animation is complete, called once per matched element.

- #### version added: 1.1 jQuery.speed( settings )

  - settings
    Type: PlainObject
    - duration (default: `400`)
      Type: Number or String
      A string or number determining how long the animation will run.
    - easing (default: `swing`)
      Type: String
      A string indicating which easing function to use for the transition.
    - complete
      Type: Function()
      A function to call once the animation is complete.

The `$.speed()` method provides a way to define properties, such as `duration`, `easing`, and `queue`, to use in a custom animation. By using it, you don't have to implement the logic that deals with default values and optional parameters.

This method is meant for plugin developers who are creating new animation methods. Letting `$.speed()` do all the parameter hockey and normalization for you, rather than duplicating the logic yourself, makes your work simpler. An example of use can be found in the animated form of `.addClass()` of jQuery UI.