Biginteger

[Ali Gilani]

i wrote a program which exceeded the ranges of int so would print a constant value. At the Sun forums, they said to use BigInteger.

 import java.math.BigInteger;
 
public class Test {
    public static void main(String[] args) {
        BigInteger two = BigInteger.valueOf(2);
        for (int n=0; n<300; ++n)
            System.out.println(two.pow(n));
    }
}
 

the code allows any number to be shown. i looked up the docs on the Math class but could not understand how to use any of its objects. for example

what does this mean ? BigInteger.valueOf(2)

and also, in the docs
multiply(BigInteger val) is present which says Returns a BigInteger whose value is (this * val) how do i use it in my programs? i mean what is the format?


Ali

[Carl Pettersson]

BigInteger.valueOf(2) returns an BigInteger with the value 2. So, you declare two to be a BigInteger with the value 2.
Multiply() also returns the result of the operation, so you do

BigInteger myBigInt = BigInteger.valueOf(2);
myBigInt = myBigInt.add(myBigInt);

After this, myBigInt is a BigInteger with value 4, since you added it to itself, and 2 + 2 = 4.
Same goes for the other, such as BigInteger.multiply().