Java/Android: Why does multiplying with a fraction equal 0?

Asked May 12 '16 at 18:18

Active May 12 '16 at 18:18

Viewed 37 times

I have come upon this problem.

I am working in android and I am trying to calculate a int value.

I can use this code:

int newCenterY = getHeight() * 3 / 5;

and it will work fine.

However, if I use this code:

int newCenterY = (3 / 5) * getHeight();

then android studio will warn me with: *(3 / 5) * getHeight(); can be replaced with 0* and it will indeed result in 0.

Are those two pieces of code not the same thing?

asked May 12 '16 at 18:18

Linxy

1

There's no fraction type in Java. That is integer division. – Sotirios Delimanolis May 12 '16 at 18:19
1

http://stackoverflow.com/questions/7220681/division-of-integers-in-java – Sotirios Delimanolis May 12 '16 at 18:19
`float centerY = (3.0 / 5) * getHeight();` – Tyler Sebastian May 12 '16 at 18:20
Your division lead to integer. Which is less than 0 so its will rounded to zero. An integer can't be in double (fraction). As @Sotirios said. – Sush May 12 '16 at 18:25

0 Answers0