JavaScript String toLocaleLowerCase() Method (original) (raw)

Last Updated : 16 Jul, 2024

The **String.prototype.toLocaleLowerCase() method in JavaScript is a Standard built-in object which returns the calling string value converted to a lowercase letter on the basis of the host’s current locale.

**Syntax:

str.toLocaleLowerCase()
str.toLocaleLowerCase(locale)

**Parameters:

**Returns Value:

This method returns a string of lowercase letters.

**Exceptions:

This method gives two kinds of errors, which are as follows:

The below examples illustrate the String.prototype.toLocaleLowerCase() method in JavaScript:

**Example 1: In this example, we will convert the uppercase string to a lowercase string and console it using the String.prototype.toLocaleLowerCase() method in JavaScript.

javascript `

// Input string let gfg = 'GeeKsForGeekS';

// Output with lowercase method console.log('EN-US: ' + gfg.toLocaleLowerCase('en-US')); console.log('TR: ' + gfg.toLocaleLowerCase('tr'));

// New input string let gfg1 = new String("String.prototype.toLocaleLowerCase()");

// Display output console.log('Result: ' + gfg1.toLocaleLowerCase());

`

Output

EN-US: geeksforgeeks TR: geeksforgeeks Result: string.prototype.tolocalelowercase()

**Example 2: In this example, we will convert the uppercase string to a lowercase string and console it using the String.prototype.toLocaleLowerCase() method in JavaScript.

javascript `

console.log('ALPHABET'.toLocaleLowerCase());

console.log('\u0130'.toLocaleLowerCase('tr') === 'i'); console.log('\u0130'.toLocaleLowerCase('en-US') === 'i');

let geeks = ['tr', 'TR', 'tr-TR', 'tr-u-co-search', 'tr-x-turkish']; console.log('\u0130'.toLocaleLowerCase(geeks) === 'i');

`

Output

alphabet true false true

We have a complete list of Javascript String methods, to check those please go through this JavaScript String Complete Reference article.

**Supported Browsers:

The browsers supported by the String.prototype.toLocaleLowerCase() method are listed below: