Mainly defines few changes to the object / property code. which allows to make a object immutable.
- Now properties can be blocked from being extended using
Clearly explained here by John - http://ejohn.org/blog/ecmascript-5-objects-and-properties/
We now have native bind() method on functions which takes in a context and returns a function which binds the function on which it is called to the scope given to bind.
We also have map / reduce function in array class.
They also made undefined immutable.