C位屏蔽和操作问题

Question

Im new to C and im having trouble understanding the usage of bit masking operations. For example i have the following code

if((input & 0x08)== 0)
{

 //Do....//

}

I took input to be the int value 00000111 , which is 7 in binary and hex, but when i do this comparison it evaluates as false (never entering the if statement).

here is what i understand and what should happen

          00000111  input
        & 00001000  0x08
         ------------
          00000000  answer

So my question is how can i get the correct output.

Answer 1

int main(){
        int input = 7;

        if((input & 0x08)== 0)
        {
                printf("Hello!\n");
        }

        return 0;
}

You are right, this program prints "Hello!".

There must be another problem in your code. Try always to create functions and test the most simple examples.

Try to print the value of input before the if statement.

Hope it helps.