c - if statement integer

Question

I think this is a simple question, but I'm struggling with the following. In my example I have the following statement (language is C):

int foobar

if (foobar)
{
// do something.
}

Now, if I am correct about this, this statement is true when foobar is not zero. So it should be much the same as if (foobar!=0).

But what happens if foobar becomes a negative number?

Answer 1

negative or positive. Anything that's not a 0 is a true value in if

Also, Consider a negative number: -1

-1 in C internally is represented as: 0xFFFFFFFF, in which case, it would be a positive number if I cast it to unsigned integer.

But after the advent of C99 standard compilers, I suggest you use <stdbool.h> instead. Makes the guessing work a lot less:

Read here about stdbool.h