EffectTiming.iterations - Web APIs 编辑

Experimental

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The Web Animations API dictionary EffectTiming's iterations property specifies the number of times the animation should repeat. The default value is 1, indicating that it should only play once, but you can set it to any floating-point value (including positive Infinity defaults to 1, and can also take a value of Infinity to make it loop infinitely. 

Element.animate(), KeyframeEffectReadOnly(), and KeyframeEffect() all accept an object of timing properties including iterations. The value of iterations corresponds directly to AnimationEffectTimingReadOnly.iterations in timing objects returned by AnimationEffectReadOnly, KeyframeEffectReadOnly, and KeyframeEffect.

Syntax

var timingProperties = {
  iterations: numberOfIterations
};

timingProperties.iterations = numberOfIterations;

Value

A floating-point value specifying the number of times the animation sequence will play through. Any value from 0 (don't play the animation at all) to positive Infinity (run the animation indefinitely) is supported. Defaults to 1, meaning the animation sequence plays through once then stops automatically.

Exceptions

TypeError

An attempt was made to set the value of this property to a negative number or NaN. The property's value is left unchanged.

Examples

In the Forgotten Key example, Alice waves her arm up and down the entire time the page is open by passing Infinity as the value for her iterations property:

// Get Alice's arm, and wave it up and down
document.getElementById("alice_arm").animate([
  { transform: 'rotate(10deg)' },
  { transform: 'rotate(-40deg)' }
], {
  easing: 'steps(2, end)',
  iterations: Infinity,
  direction: 'alternate',
  duration: 600
});

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• Web Animations API
• Element.animate(), KeyframeEffectReadOnly(), and KeyframeEffect() all accept an object of timing properties including this one.
• The value of this property corresponds to the one in AnimationEffectTimingReadOnly (which is the timing object for AnimationEffectReadOnly, KeyframeEffectReadOnly, and KeyframeEffect).
• CSS's animation-iteration-count