Unary Operators

There is only one unary operator, and that is - . This operator turns an integer into it's negative (or positive) counterpart.

One edge case I will go over, however, is the use of this operator on the smallest integer. As you should know from the previous section, the smallest representable integer in 32 bits is $-2147483648$. So what happens if we do the following:

int a = -2147483648;
int b = -a;

Now I didn't really go over this in the previous section, but to go from a negative number to a positive number, you basically follow the same procedure, so if we have $-109$, which is represented as such: 10010011. We can then flip the bits, getting us 01101100, and add 1, getting us 01101101, which gets us back $109$.

In the code block above, we have the smallest integer value, which is represented as such 10000000000000000000000000000000. Lets try and switch the sign of this. First we flip all the bits: 01111111111111111111111111111111. Now, when we add 1 to this, we will get back our original binary, which is 10000000000000000000000000000000 .

Keep in mind this edge case, as it's often something that programmers overlook.