Why i get a rectangular figure as output for this code?

Question

#include <iostream>
using namespace std;

int main() {
unsigned char b = 23;
if(b){
cout <<b;
}

return 0;
}

Answer 1

see the ascii table: http://en.cppreference.com/w/cpp/language/ascii
printable characters start at 33.(32 if you include space)

23 is ETB (end of transmission block) and is non-printable