JavaScript toLowerCase()

Use the JavaScript toLowerCase() String method to convert a given string into a lowercase letter string. This method does not change the original string.

string.toLowerCase()

JavaScript toLowerCase

Simple example code converts JavaScript String to be all lower case.

<!DOCTYPE html>
<html lang="en">
<body>
  <script>
    var s1 = "ALPHABET"
    console.log(s1)
    console.log(s1.toLowerCase())
  </script>
</body>
</html>

Output:

Just an example for toLowerCase(), toUpperCase() and a prototype for the not-yet-available toTitleCase() or toProperCase():

String.prototype.toTitleCase = function() {
  return this.split(' ').map(i => i[0].toUpperCase() + i.substring(1).toLowerCase()).join(' ');
}

String.prototype.toPropperCase = function() {
  return this.toTitleCase();
}

var OriginalCase = 'Your Name';
var lowercase = OriginalCase.toLowerCase();
var upperCase = lowercase.toUpperCase();
var titleCase = upperCase.toTitleCase();

console.log('Original: ' + OriginalCase);
console.log('toLowerCase(): ' + lowercase);
console.log('toUpperCase(): ' + upperCase);
console.log('toTitleCase(): ' + titleCase);

Output:

Original: Your Name
toLowerCase(): your name
toUpperCase(): YOUR NAME
toTitleCase(): Your Name

Using in a Function:

function convertToLowerCase(input) {
    return input.toLowerCase();
}

let result = convertToLowerCase("JavaScript Is Fun!");
console.log(result); // Output: "javascript is fun!"

Handling User Input:

let userInput = prompt("Enter some text:");
let lowerInput = userInput.toLowerCase();
console.log("You entered:", lowerInput);

Comparing Strings Case-Insensitively:

let str1 = "Apple";
let str2 = "apple";

if (str1.toLowerCase() === str2.toLowerCase()) {
    console.log("The strings are equal (case-insensitive).");
} else {
    console.log("The strings are not equal.");
}

The toLowerCase method is often used when you need to perform case-insensitive comparisons or to standardize user input.
It does not modify the original string but returns a new string with all characters in lowercase.
It can be particularly useful in form validation or processing data from various sources to ensure uniformity.

By using the toLowerCase method, you can effectively manage and compare strings in a case-insensitive manner, ensuring that your JavaScript code handles text data more robustly.

Do comment if you have any doubts or suggestions on this method examples.

Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version

JavaScript toLowerCase() | String method