What is the correct way to check for string equality in JavaScript ?

In this article, we will see the correct way to check for string equality in JavaScript. Whenever we need to compare the string we check for string equality by using different approaches. A strict equality operator is also one of the methods of comparison.

A few methods are explained below:

Method 1: Using strict equality operator

This operator checks for both value and type equality. it can be also called as strictly equal and is recommended to use it mostly instead of double equals

Example: In this example, we are checking the equality of the strings by using the strict equality (===) operator.

Javascript

const str1 = 'geeks for geeks';
const str2 = 'geeks for geeks';

if (str1 === str2) {
  console.log('The strings are equal ');
} else {
  console.log('The strings are not  equal');
}

Output

The strings are equal 

Method 2: Using double equals (==) operator

This operator checks for value equality but not type equality. 

Example: In this example, we are checking the equality of the strings by using the double equals(==) operator.

Javascript

const numStr = '42';

if (numStr == 42) {
  console.log('The values are equal');
} else {
  console.log('The values are not equal');
}

Output

The values are equal

Method 3: Using String.prototype.localeCompare() method

This method compares two strings and returns a value indicating whether one string is less than, equal to, or greater than the other in sort order. 

Example: In this example, we are checking the equality of the strings.

Javascript

const str1 = 'hello';
const str2 = 'geeks for geeks';

const comparison = str1.localeCompare(str2);

if (comparison === 0) {
  console.log('The strings are equal');
} else {
  console.log('The strings are not equal');
}

Output

The strings are not equal

Method 4: Using String.prototype.match() method

This method tests a string for a match against a regular expression and returns an array of matches. 

Example: In this example, we are checking the equality of the strings.

Javascript

const str1 = 'hello geeks';
const str2 = 'hello geeks';

const match = str2.match(str1);

if (match) {
    console.log('The strings are equal');
} else {
    console.log('The strings are not equal');
}

Output

The strings are equal