AnimationEffectTimingReadOnly.iterationStart

The iterationStart property of AnimationEffectTimingReadOnly represents which repetition the animation begins at and its progress through it.

Syntax

// Getting the iterationStart
var animationStartingPoint = animation.effect.timing.iterationStart;

// Setting the iterationStart 
animation.effect.timing.iterationStart = 5.9;

Value

A floating-point value whose value is at least 0 and is not +Infinity, indicating the offset into the number of iterations the animation sequence is to run at which to start animating. iterationStart represents the iteration index at which the animation effect begins as well as its progress through that iteration.

Usually you'll use a value between 0.0 and 1.0 to indicate an offset into the first run of the animation at which to begin the animation performance, but any positive, non-infinite value is allowed. Since all animations' iteration indexes start at 0, a value of 0.5 would start the animation halfway through its first iteration or loop. Meanwhile, a value of 1.2 means the animation will begin playback 20% of the way through its second iteration, and so forth.

Specifications

Browser compatibility

[1] The Web Animations API is only enabled by default in Firefox Developer Edition and Nightly builds. You can enable it in beta and release builds by setting the preference dom.animations-api.core.enabled to true, and can disable it in any Firefox version by setting this preference to false.

See also

• Web Animations API
• AnimationEffectTimingReadOnly and its mutable subclass AnimationEffectTiming.
• AnimationEffectReadOnly.timing — this returns one of the above, depending on the mutability of its parent.