what is wrong with this if-statement

Question

I have absolutely no idea what is wrong with this if statement, when I sent values lon = -3 and lat = 7 it should return false but it doesn't.

  if (b < 0 && ((lon > 8 && lon < 0) || (lat > 8 && lat < 0)))
  {

    return false;
  }
  else
  {
    return true ;
  }

Answer 1

decomposing each value...

int lon = -3;
int lat = 7;

  if (b < 0 && // i don't know b value
            ((-3 > 8 && //false
            -3 < 0)     //true
     || (7 > 8 && //false
     7 < 0 //false
     ))) 
  {

    return false;
  }
  else
  {
    return true ;
  }

it results in int lon = -3; int lat = 7;

  if (b < 0 && // i don't know b value
            (false || false)) 
  {

    return false;
  }
  else
  {
    return true ;
  }

and finally is:

  if (false) 
  {

    return false;
  }
  else
  {
    return true ;
  }

then it return true!

Answer 2

Though the logic flawed with this if statement, maybe there is still something to be learned here. Instead of evaluating the if statement and then returning either true or false , you could clean that up a bit and just do something like:

return b < 0 && ((lon > 8 && lon < 0) || (lat > 8 && lat < 0))

But back to the logical error, perhaps your understanding of how the inequality operators work. It would make more sense if you did something like lon > 0 && lon < 8 which would read as longitude is greater than zero and less than eight .

Answer 3

If i am reading your statement correct you will never ever get false. To get false lon must me less than zero AND more than 8 ... that is not possible. The same case with lat.