Bitwise operation result and booleans

Question

The code that frustrates me is as follows:

bool a = 0x00000FF0 & 0x00000FF0 == 0x00000FF0;
if (a) {
  Serial.println("True");
} else {
  Serial.println("False");
}

This prints "False". I really can't understand why. Some more tests:

bool a = 0x00000FF0 & 0x00000FF0 == 0x00000FF0;
Serial.println(a);

prints 0.

And:

unsigned long a = 0x00000FF0 & 0x00000FF0;
Serial.println(a, HEX);

prints FF0.

Answer 1

Operator precedence, compile with warnings:

warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses]

Change to

bool a = (0x00000FF0 & 0x00000FF0) == 0x00000FF0;