Java Decimals formatting

Question

How to number formating with Java in various scenarios:

1. if the value is 0,then output will be zero.
2. if the value 1,then output will be 1.
3. if the value is 1.2,then output will be 1.20.
4. if the value is 1.20,then output will be 1.20.

So it means if the input value has decimals then i have to apply numberformat to two decimal places otherwise not required.

• Will: There's a class for that! http://docs.oracle.com/javase/6/docs/api/java/text/DecimalFormat.html
• Nishant: have you googled? Have you looked decimatFormat? docs.oracle.com/javase/6/docs/api/java/text/DecimalFormat.html
• Hauke Ingmar Schmidt: How do you get the value, i.e. what Java type?
• Anton: stackoverflow.com/questions/264937/… and stackoverflow.com/questions/153724/… should do it.

Answer 1

One DecimalFormatter isn't going to work for the case of no decimal and the case of two decimal places.

Here's some code that meets all 4 of your conditions:

 DecimalFormat formatter1 = new DecimalFormat("0");
 DecimalFormat formatter2 = new DecimalFormat("0.00");
 double[] input = {0, 1, 1.2, 1.265};
 for (int i = 0; i < input.length; i++) {
 double test = Math.round(input[i]);
 if (Math.abs(test - input[i]) < 1E-6) {
 System.out.println(formatter1.format(input[i]));
 } else {
 System.out.println(formatter2.format(input[i]));
 }
 }

Edited to add: For jambjo, a version that manipulates the String after the DecimalFormatter.

 DecimalFormat formatter2 = new DecimalFormat("0.00");
 double[] input = {0, 1, 1.2, 1.265};
 for (int i = 0; i < input.length; i++) {
 String result = formatter2.format(input[i]);
 int pos = result.indexOf(".00");
 if (pos >= 0) {
 result = result.substring(0, pos);
 }
 System.out.println(result);
 }

• jarnbjo: What about inputs like 1.002?
• Gilbert Le Blanc: @jarnbjo: An input of 1.002 would display as 1.00. It's up to user914357 if that's acceptable or not. I assumed user914357 was dealing with money with at most 2 decimal places.
• user914357: @: but i need output value as double not string.if i do Double.parseDouble(formatter1.format(input[i])) ,i am loosing decimal place.
• Gilbert Le Blanc: @user914357: Why do you need the output value as a double? You already have the input value. Your question is about the display of a double, which is usually done with a String.
• user914357: @my input value is string not double.After conversion i need double value with above mentioned format.

Answer 2

See http://docs.oracle.com/javase/6/docs/api/java/text/DecimalFormat.html . An example of such format would be:

double input = 1.2;
DecimalFormat formatter = new DecimalFormat("0.00");
String result = formatter.format(input);

Decimal symbol (as well as other symbols used in the result string) will be dependent on system locale (unless set otherwise) - see http://docs.oracle.com/javase/6/docs/api/java/text/DecimalFormat.html#setDecimalFormatSymbols%28java.text.DecimalFormatSymbols