Java: Peculiar division behviour

Question

I would expect System.out.println(13 / 31) to print 0.419354838709677.

It prints 0.0. Why?

I don't believe you that the code you've posted prints `0.0`. — Sotirios Delimanolis, Mar 12 '15 at 23:57
@SotiriosDelimanolis try it. It does. If it does not, post what you get. — Scruffy, Mar 12 '15 at 23:57
It definitely does not return `0.0`. `0`, sure, but not `0.0`. — Sotirios Delimanolis, Mar 12 '15 at 23:58
@SotiriosDelimanolis further research on my part shows that you were right. My code was printing the return value of a method which returned a `double`. — Scruffy, Mar 13 '15 at 00:01
The value of `13/31` is an `int`, so the `println(int)` method got invoked and could not have printed a floating point value. You must have invoked the overloaded method which takes a `float` or `double`. I'm explaining my reasoning. — Sotirios Delimanolis, Mar 13 '15 at 00:04
@SotiriosDelimanolis there was never a call to `println(int)`, only `println(double)`. — Scruffy, Mar 13 '15 at 00:07
Right, so you would never have gotten the output you showed us. — Sotirios Delimanolis, Mar 13 '15 at 00:18

score 1 · Accepted Answer · answered Mar 12 '15 at 23:56

1

because you are dividing an int with an int therefore the result will be an int

try

System.out.println(13.0 / 31)

or

System.out.println((float)13 / 31)

answered Mar 12 '15 at 23:56

Scary Wombat

1 Answers1