number formatting????

[Kate Zoy]

i have an int (unknown lenght) that i need to format so there's a comma every 3 digits, like "1,000,203,2203". I know about DecimalFormat df1 = new DecimalFormat(), but I'm not quite sure what to put in the parentheses. If I knew the int was 4 digits, I could do "0,000", but I'm not sure how to go about formatting an unknown number of digits. Let me know!
Thanks!

[Kate Zoy]

Turns out that even though I still don't know how to format my number, I have a bigger problem... I take in a string, which could be an integer of any length, and I parse it into an integer. Turns out that Integer.parseInt() doesn't work (in my case) for integer longer than 9 digits! I'm not sure what is going on! Help! Am i using the wrong type? Are integers not allowed 10 digits or more?
Let me know!
Thanks Alot!

[Tim West]

You're right - Integers (and ints) are stored in four bytes, and so are limited in size from -(2^31) to 2^31-1. I can't remember exactly what those numbers are but it's around 2 billion I think - so yes, 9 digits at most.

In any case, use longs for a bigger range (-(2^63) to 2^63-1), or consider the BigInteger class if you truly need no boundaries. You can use the constructor that takes a String parameter to parse into a BigInteger.

Cheers,


--Tim

[Tim West]

Seems people politely ignored my mistake. 2 billion (2 000 000 000) is of course 10 digits, not 9.

In any case, the actual range for ints is [-2,147,483,648 to 2,147,483,647]. For longs it's [-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807].



--Tim

[Eddie Vanda]

Hi Tim,

Just a light hearted technical comment, on a multimeter that would be called "nine and a half digits"!

Ed

[zak miller]

 
import java.text.*
 
public class formatting {
 
public static void main (String [] args) {
   int num = 538927393;
 
NumberFormat formatter = NumberFormat.getNumberInstance();
String number = formatter.format(num);
}
}

Should get 538,927,393

[Kate Zoy]

Thanks, that helps alot! I'll go try the BigInteger right now!
Thanks again,
Kate