The LowerCase(s) calling sequence changes each alphabetic character in the string s to lowercase and returns the result in a new string. The string s remains unchanged.

The UpperCase(s) calling sequence changes each alphabetic character in the string s to uppercase and returns the result in a new string. The string s remains unchanged.

The OtherCase(s) calling sequence changes each alphabetic character in the string s to the opposite case and returns the result in a new string. The string s remains unchanged.

See StringTools[IsLower] and StringTools[IsUpper] for definitions of lower and uppercase characters.

These commands all accept an optional, second argument rng, a range that specifies a substring of the input s to be affected by the operation. Only characters within the given range are changed.