Decimal format in JAVA !!!!!!!!

joePC · 10-02-2004 02:54PM #1

I have 3 input dialogs taking 3 values that are then mulitpyed, is there any way of setting it so that only 2 decimal places are shown,

e.g. 3.22 instead of

3.22222222222222222222222222

I'll post the code if you want but its a bit long, if you could give me some code examples that would be great.

Thanks loads in advance..

Thanks joePC...

joePC · 10-02-2004 02:55PM

I've found all the articals on the java site but it still doesnt make much sence to me, "Im new @ the java"

Thanks joePC

Kevok · 10-02-2004 03:04PM

Dirty method, sure theres probably a better way but;

Multiply the answer by 100. Cast it into an integer to drop all the sub decimal places, then divide by 100 casting into a double or float. Then return the double/float.

[Edit]You're new at Java sorry:

int temp = (int)answer*100; // (int) casts the number into an integer dropping everything below the .
return ((double)temp/100);// (double) does the same for decimal

[/Edit]

joePC · 10-02-2004 03:27PM

Thanks for that Kevok that works perfectly..

Thanks joePC

davej · 10-02-2004 03:35PM

Funnily enough there is a class called..ahem DecimalFormat that you can use.

java.text.DecimalFormat df=new DecimalFormat("0.00");
float f = 10.2334343556;
System.out.println(df.format(f));

davej

Civilian_Target · 10-02-2004 03:37PM

Does that save the result back into float f or do you have to use it in the form

float newvar = df.format(f);

?

davej · 10-02-2004 03:39PM

it returns a string...
(edited my previous post before i saw your question)

davej

Karoma · 10-02-2004 03:46PM

if it's just for the returned result, return as a String and format

hussey · 10-02-2004 05:54PM

and to revert a string back to a float :

/* assume var num is a float, and word is the string value*/
try {

      num = java.lang.Float.parseFloat(word);

}catch (NumberFormatException nfe) {
      system.out.println("Number format exception : make sure \"" + word + "\" is valid");
}

Decimal format in JAVA !!!!!!!!

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