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# scrollViewWillBeginDecelerating(_:)

Tells the delegate that the scroll view is starting to decelerate the scrolling movement.

```
optional func scrollViewWillBeginDecelerating(_ scrollView: UIScrollView)
```

## Parameters

`scrollView`

The scroll-view object that’s decelerating the scrolling of the content view.

## Discussion

The scroll view calls this method as the user’s finger touches up as it’s moving during a scrolling operation; the scroll view continues to move a short distance afterwards. The [`isDecelerating`](/documentation/UIKit/UIScrollView/isDecelerating) property of [`UIScrollView`](/documentation/UIKit/UIScrollView) controls deceleration.

---

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