How to remove all subviews of a view in Swift?

Following task - remove all subViews of current view. Let's see how we can implement this.

For example we create UIView and add UILabel to it.

var containerView = UIView()
containerView.addSubview(UILabel(frame: CGRect.zero))

1. Simple For Loop

for subView in containerView.subviews {
    subView.removeFromSuperview()
}

2. ForEach Loop

containerView.subviews.forEach {
    $0.removeFromSuperview()
}

3. Using Map Function

containerView.subviews.map { $0.removeFromSuperview() }

4. Making Extension

If we want to make removing enable for all views in project then let's create Extension.

extension UIView {   
    func removeAllSubView() {
        self.subviews.forEach { $0.removeFromSuperview() }
    }
}

containerView.removeAllSubView()

5. Going Universal with Generics

We can go further and make our Extension universal with Generics. Now You can specify which type of subViews You want to remove.

extension UIView {
    
    func removeAllSubViewOfType<T: UIView>(type: T.Type) {
        self.subviews.forEach {
            if ($0 is T) {
                $0.removeFromSuperview()
            }
        }
    }
}

containerView.removeAllSubViewOfType(type: UILabel.self)

6. The Same but Using Filter and Map Functions

The same as above. But here we use chain of High-order functions.

extension UIView {
    
    func removeAllSubViewOfTypeUsingHOF<T: UIView>(type: T.Type) {
        self.subviews.filter({ $0 is T }).map({ $0.removeFromSuperview() })
    }
}

containerView.removeAllSubViewOfTypeUsingHOF(type: UILabel.self)