How do I round a double to one decimal place? [closed]

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Closed 6 years ago.

I am trying to get a random double returned to me in the format #.# however I am getting a value of something to this effect: 0.9395772067578356

How do you force only a one decimal return on a random double as I cannot put paraments in the .nextDouble.

        myRandomNumGenerator = new Random();
        loadedValue = myRandomNumGenerator.nextDouble();

回答1:

DecimalFormat oneDigit = new DecimalFormat("#,##0.0");//format to 1 decimal place

System.out.println(oneDigit.format(anyVariable)); //generic usage

loadedValue = Double.valueOf(oneDigit.format(loadedValue));//specific usage posted in comments

回答2:

I don't think you can force a one place return. You can just make it print the one place, however.

System.out.printf("%.1f", loadedValue);

That will print the value to one place.

来源：https://stackoverflow.com/questions/15193739/how-do-i-round-a-double-to-one-decimal-place