Whether or not c is a printable character other than the space character.
1 assert( isGraphical('1')); 2 assert( isGraphical('a')); 3 assert( isGraphical('#')); 4 assert(!isGraphical(' ')); // whitespace is not graphical 5 assert(!isGraphical('\n')); 6 assert(!isGraphical('\0')); 7 8 // N.B.: Unicode graphical characters are not regarded as such. 9 assert(!isGraphical('á'));