JavaScript String toUpperCase() Method

The toUpperCase() method is used to convert all letters in a string to uppercase. It helps standardize text for comparison or display.

• Converts all lowercase letters to uppercase.
• Special characters and digits remain unchanged.
• Letters that are already uppercase stay the same.

Syntax:

str.toUpperCase()

Parameters:

This method does not accept any parameter.

Return value:

The toUpperCase() method returns a modified version of the original string. It creates a new string with all letters converted to uppercase.

• Returns a new string.
• All lowercase letters are converted to uppercase.
• The original string remains unchanged.

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

[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. 

[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.