C ++中的XOR运算符和char

Question

Given the following code fragment in C++:

char a = 0x0a;
char b = 0x80;
char c = a ^ b;

what will happen behind the screen? When I use cout to output c, there was no output. Will the char a and char b be converted to binary format? what's the format of c?

Answer 1

c will be 0x8a, which is usually not a printable character, see (eg) http://www.unicodetools.com/unicode/img/latin-iso-8859-1.gif

(neither are 0x0a (line feed) or 0x80)

cout will print the character corresponding to the value of c for char arguments, that's why you don't see any output.

You may want to use printf to print the numeric value of c, or cast c to an int.

You may also be interested in this question, which discusses printing binary numbers in C: Is there a printf converter to print in binary format?

Answer 2

All numbers in a computer are in binary format.

0x0a , aka 10 (ten), is represented as

1010

and 0x80 , aka 128 , is represented as

10000000

If you xor those, you get 138.

Apparently, your terminal doesn't output anything useful if you print the char 138.