Out of curiosity, what happens when you change line 2 to the following?

Not obvious !! Try comparing the different results with the following:

tkt → result 1.0 → 60.0 2.0 → 30.0 3.0 → 15.0 4.0 → 7.0 5.0 → 3.0 That's the other way around. It rounds at tkt = 4.0 and 5.0 but still keeps the .0 in the end.

Shouldn't the result of tkt=3 be 20; 4 be 15; and 5 be 12; and 6 be 10; then, 7 be 8.6; 8 be 7.5; 9 be 6.7; etc? Your numerical results do not match (regardless of how they are returned). You results seem to be for 60/(2^tkt).

Oh yes, it is. Theoretically, it is 0 → 120 1 → 60 2 → 30 3 → 15 4 → 7.5 5 → 3.75 (Other values are not possible.) Sorry for that. Still, the extra .0 only go away when using if-else over ?-: for some reason.

Not sure where the double should go, now it is pretty much everywhere with more ( ) than needed but it doesn't seem to matter either. Still same results.

I was thinking something like this: Or, maybe just adding the '.0' without the '(double)' does the trick:

Must be the way it compiles the operation. Probably cannot have two different Type outputs for the operation. Sort of like a return from a method; the most specific type that can return all possible values is probably used.

If you have code like A ? B : C, then A must be boolean, whereas B and C must be the same type. If you have int and int, you get int. Double and double makes double. Java has a set of rules about how to convert the two expressions if they are of different types: if you have int and double, the type is double. Hence although you aren't executing the other branch, the type is determined at compile-time by looking at both halves of the expression. Because you're then converting to String, you see a .0 on the end if you have arranged it to be a double, or without .0 if you get it into an int. In the first line of the original post, you made an int (it's int in both parts of the conditional) whereas on the second line of original post, you made a double (int and double means both are changed to double to have the same type).

Okay, I didn't know that they have to be the same type (or they will become the same type automatically). I thought it would be the same as doing the longer way with if and else. Thank you both for explaining!