Hide decimal places in Double when not in use

Question

I have a simple code:

int num1 = <user input>;
int num2 = <user input>;
String operation = <user input>;
double result = num1 operation num2;

Is there a way to format my output such that it will only display the decimal values if they are non-zero?

i.e.
5/3 = 3.67
5+3 = 8

You might want to check [this post](https://stackoverflow.com/questions/38424291/format-float-to-show-decimal-places-if-is-not-zero-java). — Whooper, Jan 31 '18 at 07:08
you can check `Math.ceil(x.y) == Math.floor(x.y)` if they are equal means there is no decimal part, hence you can safely downcast to `int`, similar answer here https://stackoverflow.com/a/15963957/3521116 — warl0ck, Jan 31 '18 at 07:08
use decimalformat `DecimalFormat df = new DecimalFormat("###.#"); df.format(result)` — , Jan 31 '18 at 07:10
Of course there is. Have you considered asking Google first? — shmosel, Jan 31 '18 at 07:16
I tried `DecimalFormat df = new DecimalFormat("###.####");` and it makes `8.0` into `8`, but `3.7` is now `4`. What is going on ? — Dranreb Benedicto, Jan 31 '18 at 07:27

Oghli · Answer 1 · 2018-01-31T08:17:56.553

Try this way and see the results :

Scanner in = new Scanner(System.in);
DecimalFormat df = new DecimalFormat("##.####");
double num = in.nextDouble();
String result = df.format(num);
System.out.println(result);

Output:

3.67
3.67
BUILD SUCCESSFUL (total time: 5 seconds)

8
8
BUILD SUCCESSFUL (total time: 2 seconds)

Update:

you can try this program that work for your requirements:

            Scanner in = new Scanner(System.in);
            DecimalFormat df = new DecimalFormat("##.####");
            double result = 0;
            int num1 = in.nextInt();
            int num2 = in.nextInt();
            String operation = in.next();

            if(operation.equals("/")){
                result = (double)num1 / num2;
            }
            else if(operation.equals("*")){
                result = num1 * num2;
            }
            else if(operation.equals("+")){
                result = num1 + num2;
            }
            else if(operation.equals("-")) {
                result = num1 - num2;
            }
            System.out.println(df.format(result));

test case:

5
3
/
1.6667
BUILD SUCCESSFUL (total time: 3 seconds)

Hide decimal places in Double when not in use

1 Answers1