Can someone explain me this... .0

In Java, integers in code are of type int by default. If two int types are divided, the result is also just an int type. So you don't get an exact result: 5 / 3 == 1; // int 1 and not 1.6666 7 / 3 == 2; // int 2 and not 2.3333 etc. If you want to get an exact value, that means you want a double type as the result, like 1.6666. But to do that, at least one of the two starting numbers ( 5 and 3 ) must be of type double, which can be done this way: 5 / 3.0 7.0 / 3

int x = 5,
int y = 3;

double z = x / (y+0.0);
double w = x*1.0 / y ;