toUpperCase method

Converts all characters in this string to upper case. If the string is already in all upper case, this method returns this.

String toUpperCase( )

Converts all characters in this string to upper case. If the string is already in all upper case, this method returns this.

'alphabet'.toUpperCase(); // 'ALPHABET'
'ABC'.toUpperCase();      // 'ABC'

This function uses the language independent Unicode mapping and thus only works in some languages.