Enthuware

Is there some easy way to determine what type will a result of mathematical expression be? Like here, because it's divided by 4.0, it returns double. Are there some other simple rules to remember?

There can be only four return types in case of numeric - int, long, float, and double.
The type of the expression will be the largest required. i.e. if the largest constituent in long, then the return type will be long.

For example:

long x = 10L;
int p = x/2; //will not work because x/2 is long
long p = x/2.0; //will not work because x/2.0 is now double

The return type of an expression is never a byte, char, short. For example,
byte x = 10;
byte p = x*1; //will not work because x*1 is an int.

HTH,
Paul.

Thank you, finally this is clear. I have not found this anywhere before and yet it is so simple.

You say that "There can be only three return types in case of numeric - int, long, float, and double." That is FOUR types, right? How do you know when float will be returned versus when double will be returned?

Yes, I should have written four above (corrected). Thanks for pointing it out.
float will be returned when the largest component of an expression is a float, for example:
int a = 1;
float b = 2.0f;
double d = 2.0;
float c = a*b; //valid, a*b will return a float because the larget component of a*b is b, which is a float.
float x = a*d; //invalid because a*d will return a double

Paul.

Thank you Paul that is a great explanation.