Check if string is empty in JavaScript

In this tutorial, you are given a string. You should check if given string is empty or not.

Solution

A string is said to be empty if its length is 0, or if it equals an empty string. To check if string length is 0, we can use String.length property and comparison equal-to operator.

To check if string equals an empty string, we can use comparison equal value and equal type operator.

Program

1. In the following program, we are given a string in str. We shall check if string str is empty using string length property.

let str = '';
if ( str.length == 0 ) {
    console.log('empty string');
} else {
    console.log('not an empty string');
}

We have used the condition as a boolean expression in if-else statement

2. In the following program, we are given a string in str. We shall check if str is empty using equal-value and equal-type operator.

let str = '';
if ( str === '' ) {
    console.log('empty string');
} else {
    console.log('not an empty string');
}