merge two long numbers into a single long number

[ankitabhatia]

i have 2 long numbers
eg xl=12345678
xr=87654321

i want to merge these 2 nos. into a single long number
i have to do this in java..
any help would be great..thanks a lot:)

[anurag275125]

For merging two long values into a single long value, you have to first convert long data type to String and then concat these two string into a single string, then convert this string into long data type.

The code for conversion is:

public class ankitabhatia
{
    public static void main(String args[])
    {
        long l1,l2;
        l1=12345678;
        l2=87654321;
        String s1=Long.toString(l1);    // converting long to String
        String s2=Long.toString(l2);
        String s3=s1+s2;
        long l3=Long.valueOf(s3).longValue();    // converting String to long
        System.out.println(l3);
    }
}

Hope this will help you!!

[ankitabhatia]

thanks a lot :):)...

[deathhack]

@anurag275125
thank's nice solution...

[chaarmann]

Why convert to String and then back?
You can multiply the first number with a power of ten and add the second to it. That's a high magnitude quicker!

Example:
given
l1=12345678;
l2=87654321;
results in
l3=l1*100000000 + l2;

P.S: Just look at the source code of Long.toString() and you see that's a loop which divides by ten and prints the remainder into a string buffer. But you do the division only once and you don't need to allocate memory for your string object.

P.P.S:
if the length of the first number is unknown, then
you can get it with divide-and-conquer alogorithm. It's much faster than String.valueOf(i1).length() or (int)(Math.log10(i1)+1) or other ways. See http://stackoverflow.com/questions/1...gits-in-an-int