#include <iostream>
#include <cstdlib>
#include <cctype>   //for the function toupper
using namespace std;

int main()
{
	char c {'a'};   //means char c{97};
	cout << c << "\n";
	
	//Use "bitwise and" to change lowercase 'a' to uppercase 'A'.
	//(We're really changing 97 to 65.)
	//   01100001    0x61 = 'a' =  97
	// & 11011111    0xDF       = 223
	//   01000001    0x41 = 'A' =  65
	
	c &= 0xDF;   //means c = c & 0xDF;
	cout << c << "\n\n";

	char d {'b'};
	cout << d << "\n";
	d = toupper(d);   //C++ Standard Library function
	cout << d << "\n";

	return EXIT_SUCCESS;
}