Hi All,

You can add auto layout constraints by using Storyboard Interface OR by adding constraints dynamically. There are three ways to add constraint dynamically (as per Apple Inc.)

Layout Anchor is one of the way is used to add autolayout constraints dynamically.

Layout Anchors Example :-

let new_view:UIView! = UIView(frame: CGRectMake(20, 20, 100, 100));
        new_view.backgroundColor = UIColor.redColor();
        new_view.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(new_view);

        let margins = view.layoutMarginsGuide

        //this line is adding leading of new_view to leading of super view
        new_view.leadingAnchor.constraintEqualToAnchor(margins.leadingAnchor).active = true

        //this line is adding top of new_view to top of super view with 20 points constant
        new_view.topAnchor.constraintEqualToAnchor(margins.topAnchor,constant:20.0).active = true

        //this line is adding width of new_view with 100.0 points constant
        new_view.widthAnchor.constraintEqualToConstant(100.0).active = true

        //this line is adding height of new_view to width of new_view with 20 points constant
        new_view.heightAnchor.constraintGreaterThanOrEqualToAnchor(new_view.widthAnchor, multiplier: 2.0).active = true