how to make UITextView height dynamic according to text length?

this Works for me, all other solutions didn't.

func adjustUITextViewHeight(arg : UITextView) {
    arg.translatesAutoresizingMaskIntoConstraints = true
    arg.sizeToFit()
    arg.scrollEnabled = false
}

In Swift 4 the syntax of arg.scrollEnabled = false has changed to arg.isScrollEnabled = false.

In Storyboard / Interface Builder simply disable scrolling in the Attribute inspector.

In code textField.scrollEnabled = false should do the trick.

All I had to do was:

1. Set the constraints to the top, left, and right of the textView.
2. Disable scrolling in Storyboard.

This allows autolayout to dynamically size the textView based on its content.