Thread: conditional question

Good morning....
Can someone please tell me the difference between

if (variable = 0)

and

if (variable == 0)


Thanks

One is a comparison, the other is an assignment.

I understand that but if I want to check for a value do I use the first or the second....I keep getting confused....

if (variable & 0x0F) .....Seems to me that here if ANY bit in the lower nibble of variable was set I would execute

if (variable == 0x0E) .....where as here the variable MUST be 0x0E to execute

Is this correct?

So the question begs 0 is 0 wouldn't both of the above statements cause execution if variable was 0?

Well if you use the assignment operator= in an if() statement the statement will always evaluate to true. If you use the comparison operator== it will evaluate to either true or false, depending on the values used in the comparison.

For the new post:

What is the type of variable?

For bit operations is is sometimes easier to use intermediate variables to check your logic.

Code:

value = variable & 0x0F;

cout << value << '\n';

And remember that in C false is zero and true is everything else (not zero).

Also this link may be of some help when trying to figure out bitwise operations.