C++ int float casting

Question

Why is m always = 0? The x and y members of someClass are integers.

float getSlope(someClass a, someClass b) {                float m = (a.y - b.y) / (a.x - b.x);     cout << " m = " << m << "\n";     return m; } 

Answer 1

You need to use cast. I see the other answers, and they will really work, but as the tag is C++ I'd suggest you to use static_cast:

float m = static_cast&lt float &gt( a.y - b.y ) / static_cast&lt float &gt( a.x - b.x );

Answer 2

Integer division occurs, then the result, which is an integer, is assigned as a float. If the result is less than 1 then it ends up as 0.

You'll want to cast the expressions to floats first before dividing, e.g.

float m = static_cast<float>(a.y - b.y) / static_cast<float>(a.x - b.x);