1 Null is an Object
null is an empty or non-existent value.
2 NaN is a Number
3 An Empty Array Equals False
For instance, you can have an array of functions with variables inside the functions. Just like having a function inside of a function (as you may have learned already) the outer function does not have access to the variables of the inner functions. So an array can have information that cant be accessed by the comparison operator, so it can’t declare it true
4 Function Can Execute Themselves
A self–invoking expression is invoked (started) automatically, without being called. A self–invoking expression is invoked right after its created. This is basically used for avoiding naming conflict as well as for achieving encapsulation. The variables or declared objects are not accessible outside this function.