JavaScript String toUpperCase() Method

JavaScript String toUpperCase() method converts the entire string to Upper case.

This method does not affect any of the special characters, digits, and the alphabets that are already in the upper case. 

Syntax:

str.toUpperCase()

Parameters:

This method does not accept any parameter.

Return value:

This method returns a new string in which all the lowercase letters are converted to uppercase.

Example 1: In this example, we are converting the given string to uppercase.

let str = 'geeksforgeeks';
let string = str.toUpperCase();
console.log(string);

GEEKSFORGEEKS

Example 2: In this example, the method toUpperCase() converts all the lower case alphabets to their upper case equivalents without affecting the special characters and the digits. 

// JavaScript String toUpperCase() method
// to convert string to Uppercase

// Original string
let str = 'It iS a 5r&:ampe@@t Day.'

// String converted to Upper Case
let string = str.toUpperCase();

console.log(string);

IT IS A 5R&:AMPE@@T DAY.

Example 3: In this example, we are creating an array of data with elements 'javascript', 'html', and 'css'. It uses map() and toUpperCase() to convert each element to uppercase.

let data = [ 'javascript', 'html', 'css' ];

let result = data.map(data => data.toUpperCase());

console.log(result);

[ 'JAVASCRIPT', 'HTML', 'CSS' ]

Supported Browsers:

• Chrome 1
• Edge 12
• Firefox 1
• Opera 3
• Safari 1

JavaScript String toUpperCase() & toLowerCase() Method

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JavaScript String toUpperCase() & toLowerCase() Method

Javascript Program to Convert from Lowercase to Uppercase