Rounding up and down a number C++
The function you need is called round, believe it or not.
ceil
rounds UP, btw. That is, to the closest larger integer. floor
rounds down.
You don't need a function to round in C or C++. You can just use a simple trick. Add 0.5 and then cast to an integer. That's probably all round does anyway.
double d = 3.1415;
double d2 = 4.7;
int i1 = (int)(d + 0.5);
int i2 = (int)(d2 + 0.5);
i1 is 3, and i2 is 5. You can verify it yourself.
std::ceil
rounds up to the nearest integer
std::floor
rounds down to the nearest integer
std::round
performs the behavior you expect
please give a use case with numbers if this does not provide you with what you need!