String toLowerCase( )

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

'ALPHABET'.toLowerCase(); // 'alphabet'
'abc'.toLowerCase();      // 'abc'

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

Source

/**
 * Converts all characters in this string to lower case.
 * If the string is already in all lower case, this method returns [:this:].
 *
 *     'ALPHABET'.toLowerCase(); // 'alphabet'
 *     'abc'.toLowerCase();      // 'abc'
 *
 * This function uses the language independent Unicode mapping and thus only
 * works in some languages.
 */
// TODO(floitsch): document better. (See EcmaScript for description).
String toLowerCase();