JavaScript String toUpperCase()
Syntax & Examples

String.toUpperCase() method

The toUpperCase() method of the String class in JavaScript returns the calling string value converted to uppercase.

Syntax of String.toUpperCase()

The syntax of String.toUpperCase() method is:

toUpperCase()

This toUpperCase() method of String returns the calling string value converted to uppercase.

Return Type

String.toUpperCase() returns value of type String.


✐ Examples

1 Using toUpperCase() method

In JavaScript, the toUpperCase() method converts a string to uppercase letters.

For example,

  1. We define a string variable str with the value 'hello world'.
  2. We use the toUpperCase() method to convert the string to uppercase.
  3. The result is stored in the variable upperStr.
  4. We log upperStr to the console using the console.log() method.

JavaScript Program

const str = 'hello world';
const upperStr = str.toUpperCase();
console.log(upperStr);

Output

HELLO WORLD

2 Using toUpperCase() method on a string with mixed case

In JavaScript, the toUpperCase() method can be used to convert a string with mixed case letters to all uppercase letters.

For example,

  1. We define a string variable str with the value 'JavaScript'.
  2. We use the toUpperCase() method to convert the string to uppercase.
  3. The result is stored in the variable upperStr.
  4. We log upperStr to the console using the console.log() method.

JavaScript Program

const str = 'JavaScript';
const upperStr = str.toUpperCase();
console.log(upperStr);

Output

JAVASCRIPT

3 Using toUpperCase() method on a string with numbers and symbols

In JavaScript, the toUpperCase() method only affects alphabetic characters and leaves numbers and symbols unchanged.

For example,

  1. We define a string variable str with the value 'Hello 123!'.
  2. We use the toUpperCase() method to convert the alphabetic characters to uppercase.
  3. The result is stored in the variable upperStr.
  4. We log upperStr to the console using the console.log() method.

JavaScript Program

const str = 'Hello 123!';
const upperStr = str.toUpperCase();
console.log(upperStr);

Output

HELLO 123!

Summary

In this JavaScript tutorial, we learned about toUpperCase() method of String: the syntax and few working examples with output and detailed explanation for each example.