Show padding zeros using DecimalFormat

Question

I'm using DecimalFormat to format doubles to 2 decimal places like this:

DecimalFormat dec = new DecimalFormat("#.##"); double rawPercent = ( (double)(count.getCount().intValue()) /                              (double)(total.intValue()) ) * 100.00; double percentage = Double.valueOf(dec.format(rawPercent)); 

It works, but if i have a number like 20, it gives me this:

20.0 

and I want this:

20.00 

Any suggestions?

Answer 1

The DecimalFormat class is for transforming a decimal numeric value into a String. In your example, you are taking the String that comes from the format( ) method and putting it back into a double variable. If you are then outputting that double variable you would not see the formatted string. See the code example below and its output:

int count = 10; int total = 20; DecimalFormat dec = new DecimalFormat("#.00"); double rawPercent = ( (double)(count) / (double)(total) ) * 100.00;  double percentage = Double.valueOf(dec.format(rawPercent));  System.out.println("DF Version: " + dec.format(rawPercent)); System.out.println("double version: " + percentage); 

Which outputs:

"DF Version: 50.00" "double version: 50.0" 

Answer 2

Try this code:

BigDecimal decimal = new BigDecimal("100.25");  BigDecimal decimal2 = new BigDecimal("1000.70");  BigDecimal decimal3 = new BigDecimal("10000.00");  DecimalFormat format = new DecimalFormat("###,###,###,###,###.##");  format.setDecimalSeparatorAlwaysShown(true);  format.setMinimumFractionDigits(2);  System.out.println(format.format(decimal));  System.out.println(format.format(decimal2));  System.out.println(format.format(decimal3)); 

Result:

100.25  1,000.70  10,000.00