How to Check if a Variable Is Not Null in JavaScript

1. the Incorrect Way That Seems Right
2. the Correct Way to Check Variable Is Not Null

This tutorial teaches how to check if a variable is not null in JavaScript.

the Incorrect Way That Seems Right

if (myVar) {
  ...
}

This way will evaluate to true when myVar is null, but it will also get executed when myVar is any of these:

• undefined
• null
• 0
• "" (the empty string)
• false
• NaN

the Correct Way to Check Variable Is Not Null

if (myVar !== null) {
  ...
}

The above code is the right way to check if a variable is null because it will be triggered only in one condition - the variable is actually null.