How do I get fixed length decimal number in java float or double?
say, i've 22 and want to devide it with 7.
i want to get 3.14 not 3.14285.....
Joined: Mar 22, 2005
The java.text.NumberFormat class does this; check out in particular the setMaximumFractionDigits and setMinimumFractionDigits methods. Of course, then you'll have a string, but you can convert it back easily enough. [ September 29, 2005: Message edited by: Ulf Dittmer ]
1. Multiply the result times 100. 2. round() 3. Divide by 100
Joined: Sep 19, 2004
>> I want to get 3.14 not 3.14285
In fact you really don't know what the value is until you observe it. So it makes sense to display it in the form you want while preserving the maximum precision the rest of the time.
double value = 3.143423432432; System.out.printf("%.2f", value); // Prints: 3.14
Joined: Dec 06, 2001
As Rick points out, you should make a distinction between how the number is stored and how it is displayed. When doing calculations, you should store the value as precisely as possible. However, when you display it, you can use either NumberFormat or, if you can use Java 5.0 features, PrintStream.printf() for the exact formatting you want.