Javascript String toLowerCase()

The toLowerCase() method returns the string converted to lowercase.


const message = "JAVASCRIPT IS FUN";

// convert message to lowercase const lowerMessage = message.toLowerCase();
console.log(lowerMessage); // Output: javascript is fun

toLowerCase() Syntax

The syntax of the toLowerCase() method is:


Here, str is a string.

toLowerCase() Parameters

The toLowerCase() method does not take in any parameters.

toLowerCase() Return Value

  • Returns a new string representing the calling string converted to lowercase.


  • The toLowerCase() method raises TypeError when called on null or undefined.
  • The toLowerCase() method does not change the original string.

Example: Using toLowerCase() method

let str = "Hello World!";
let sentence = "Java is to JavaScript what Car is to Carpet.";

let lowercase_str = str.toLowerCase();
console.log(lowercase_str); // hello world!
let lowercase = sentence.toLowerCase();
console.log(lowercase); // java is to javascript what car is to carpet.


hello world!
java is to javascript what car is to carpet.

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