Java round to nearest .5 [duplicate]

Question

How is this possible in Java?

I have a float and I'd like to round it to the nearest .5.

For example:

1.1 should round to 1.0

1.3 should round to 1.5

2.5 should round to 2.5

3.223920 should round to 3.0

EDIT: Also, I don't just want the string representation, I want an actual float to work with after that.

Answer 1

@SamiKorhonen said this in a comment:

Multiply by two, round and finally divide by two

So this is that code:

public static double roundToHalf(double d) {     return Math.round(d * 2) / 2.0; }  public static void main(String[] args) {     double d1 = roundToHalf(1.1);     double d2 = roundToHalf(1.3);     double d3 = roundToHalf(2.5);     double d4 = roundToHalf(3.223920);     double d5 = roundToHalf(3);      System.out.println(d1);     System.out.println(d2);     System.out.println(d3);     System.out.println(d4);     System.out.println(d5); } 

Output:

1.0 1.5 2.5 3.0 3.0 

Answer 2

The general solution is

public static double roundToFraction(double x, long fraction) {     return (double) Math.round(x * fraction) / fraction; } 

In your case, you can do

double d = roundToFraction(x, 2); 

to round to two decimal places

double d = roundToFraction(x, 100);