Understanding the difference between JavaScript “undefined” and “null”

What is the difference between “undefined” and “null”?

By using the textContent property , you can output a string while also specifying the location.

Explanation of “undefined” and “null”

undefinedBoth nullindicate that no value has been set, but there are differences in their usage and meaning.

Explanation of undefined

undefined indicates that a variable is defined but has no value set.
Also, undefined is returned when an attempt is made to refer to a variable that is not defined or to refer to a property of an object that does not exist.

Explanation of null

A null is an explicit indication that a value does not exist.
Assigning null to a variable allows the variable to be empty.

Difference between “undefined” and “null” and how to use them

undefined indicates that the variable is defined but has no value set. On the other hand, null explicitly indicates that no value exists.

The usage of “undefined” and “null” is shown below.

let x; 
console.log(x); // undefined

let y = null; 
console.log(y); // null

let obj = {}; 
console.log(obj.x); // undefined

So “undefined” is something that has no value set, and “null” is something that explicitly states that the value does not exist!

Summary of the difference between “undefined” and “null

The difference between undefined and null is summarized below.

As a programmer, it is important to understand undefinedcorrectly nulland use them in appropriate situations.

Be careful not to confuse undefined with null: undefined indicates that no value is set, while null explicitly indicates that no value exists.
Remembering the correct usage will make your programming easier.