The Equality Operator (==)

The equality operator (==) checks whether two operands are the same and returns true if they are the same and false if they are different.

The Identity Operator (===)

The identity operator checks whether two operands are “identical”.

These rules determine whether two values are identical:

• They have to have the same type.
• If number values have the same value they are identical, unless one or both are NaN.
• If string values have the same value they are identical, unless the strings differ in length or content.
• If boolean values are either true or false, they are identical.
• If both values refer to the same object, array or function they are identical.
• If both values are null or undefined they are identical.