Void setIndex(String s, Char c, Int i)
s: The string
c: The character to set (may not be a NULL)
i: The position in the string
Sets the ith character of the given String to the given character. The index starts at zero.
str = "abcdefg"; setIndex(str,'-',4); // str = "abcd-fg"
An IllegalIndex exception is thrown if i is out of bounds.