Javascript undefined vs null

is one of the most widely used programming languages in the world, powering everything from simple web pages to complex web applications.

Null: A variable that is null has been explicitly set to have no value.

Syntax:

let v1 = null; typeof (var_); // "object"

Null was designed to represent the absence of an object or value, so it was given a special value of all zeros.

This made it easy for the language to check if a variable was null since it could simply check if the value was equal to zero.

Example:One of the most common is to use the triple equals (===) operator, which checks for both value and type equality.

Output:

null

Undefined: A variable that is undefined has not been assigned a value.

This means that if you declare a variable but don’t assign a value to it, the variable’s value will be undefined.

Syntax:

let var2; typeof (var2); // "undefined"

Example: Here we will check the value of our variable with the help of the triple equals (===) operator.