Double decimal formatting in Java

Question

I\'m having some problems formatting the decimals of a double. If I have a double value, e.g. 4.0, how do I format the decimals so that it\'s 4.00 instead?

Answer 1

An alternative method is use the setMinimumFractionDigits method from the NumberFormat class.

Here you basically specify how many numbers you want to appear after the decimal point.

So an input of 4.0 would produce 4.00, assuming your specified amount was 2.

But, if your Double input contains more than the amount specified, it will take the minimum amount specified, then add one more digit rounded up/down

For example, 4.15465454 with a minimum amount of 2 specified will produce 4.155

NumberFormat nf = NumberFormat.getInstance();
nf.setMinimumFractionDigits(2);
Double myVal = 4.15465454;
System.out.println(nf.format(myVal));

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