2.8.3.6 Modification

Function: string-set! str i char

i must be a valid index of str. Store char in element i of str.

NOTE Constant string literals appearing in code are to be considered immutable; mutating them leads to undefined results.

Function: string-fill! str char

Function: string-fill! str char start

Function: string-fill! str char start end

Store char in every selected element of str.