Null vs Undefined in JavaScript

Do you really know the difference between "null" and "undefined" in JavaScript? If not, let me explain.

Undefined

In JavaScript, undefined means a variable has been declared but has not yet been assigned a value. For example:

X is like a new team member in your company who hasn't been assigned any role yet.

let X;

console.log(X) 
undefined

console.log(typeof X)
undefined

Null

Null is an assignment value. It can be intentionally assigned to a variable as a representation of no value: For example:

X is like a team member in your company who has been intentionally told to do nothing as of now.

let X = null;

console.log(X) 
null

console.log(typeof X) 
object

typeof(null) will interestingly return 'object'. Unfortunately, this can be considered a bug in JS where the datatype of null is an object.]

Also, note that undefined == null will return true, meanwhile undefined === null will return false. It means null is equal to undefined but not identical(because they have different datatypes).

Happy coding :)

10daysofJSfundamentals (Day 2)