isspace method
Checks if the character is a white-space character. Standard white-space characters are: space (' '), form feed ('\f'), newline ('\n'), carriage return ('\r'), horizontal tab ('\t'), and vertical tab ('\v').
Implementation
bool isspace(String c) {
int code = _getCode(c);
return code == 32 || (code >= 9 && code <= 13);
}