java: public static boolean isValidSchemeChar(int index, char c) {if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {return true;}if (index > 0 && ((c >= '0' && c <= '9') || c == '+' || c == '-' || c == '.')) {return true;}return false;}
C#: public static bool isValidSchemeChar(int index, char c){if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')){return true;}if (index > 0 && ((c >= '0' && c <= '9') || c == '+' || c == '-' || c == '.')){return true;}return false;}