length() : Int concat(s : String) : String substr(i : Int, l : Int) : StringThe method length returns the length of the self parameter. The method concat returns the string formed by concatenating s after self. The method substr returns the substring of its self parameter beginning at position i with length l; string positions are numbered beginning at 0. A runtime error is generated if the specified substring is out of range. Substring errors are always reported as taking place on line 0.
The default initialization for variables of type String is "" (not void). It is an error to inherit from or redefine String.