Ben - 1 year ago 88

Java Question

This is a basic question but I can't find an answer. I've looked into floating point arithmetic and a few other topics but nothing has seemed to address this. I'm sure I just have the wrong terminology.

Basically, I want to take two quantities - completed, and total - and divide them to come up with a percentage (of how much has been completed). The quantities are

`long`

`long completed = 25000;`

long total = 50000;

System.out.println(completed/total); // Prints 0

I've tried reassigning the result to a double - it prints

`0.0`

Incidentally, the next step is to multiply this result by 100, which I assume should be easy once this small hurdle is stepped over.

BTW not homework here just plain old numskull-ness (and maybe too much coding today).

Answer Source

Converting the *output* is too late; the calculation has already taken place in integer arithmetic. You need to convert the *inputs* to `double`

:

```
System.out.println((double)completed/(double)total);
```

Note that you don't actually need to convert *both* of them; so long as one is `double`

, the other will be implicitly converted. But I prefer to do both, for symmetry.