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# value(forAnimatedKey:)

Returns the most recently set value for the specified key.

```
func value(forAnimatedKey key: NSCollectionViewTransitionLayout.AnimatedKey) -> CGFloat
```

## Parameters

`key`

A key whose value you set previously using the [`updateValue(_:forAnimatedKey:)`](/documentation/AppKit/NSCollectionViewTransitionLayout/updateValue(_:forAnimatedKey:)) method.

## Return Value

The last value set for the key.

## Discussion

Use this method to retrieve floating-point values that relate to laying out the contents of your collection view. The key you specify is a string that you define and that has some meaning to your layout’s implementation. At points during an interactive transition, you can assign new values to that key using the [`updateValue(_:forAnimatedKey:)`](/documentation/AppKit/NSCollectionViewTransitionLayout/updateValue(_:forAnimatedKey:)) method.

---

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