last

Returns the last character of the string. If a limit is supplied, returns a substring from the end of the string until it reaches the limit value (counting backwards). If the given limit is greater than or equal to the string length, returns self.

str = "hello"
str.last    # => "o"
str.last(1) # => "o"
str.last(2) # => "lo"
str.last(0) # => ""
str.last(6) # => "hello"