Question

I’m trying to make a program calculate the first four perfect numbers. It compiles, but when I run the program, the for-loops seem to be invisible. Like when I look at the debugger, it looks like the for-loops are just skipped over and the variables don’t exist.

public static void main(String[] args)
{
    int pNum = 2; // starting number to check
    int sum = 0; 

    for (int count = 1; count <= 4; count++) 
    {
        for (int factor = 1; factor < pNum; factor++)
        {
            if (pNum % factor == 0)
                sum += factor;
        }

        if (pNum == sum)
        {
            System.out.println(pNum + " is a perfect number.");
            count++;
        }

        pNum++; sum = 0;
    }
}

Answer 1

count = 1, pNum = 2, sum = 0
factor = 1, sum = 0
count = 2, pNum = 3, sum = 0
factor = 1, sum = 0
factor = 2, sum = 1
count = 3, pNum = 4, sum = 0
factor = 1, sum = 0
factor = 2, sum = 1
factor = 3, sum = 3
count = 4, pNum = 5, sum = 0
factor = 1, sum = 0
factor = 2, sum = 1
factor = 3, sum = 1
factor = 4, sum = 1