Perfect number program

[FilthyDust81568]

I am trying to get a program to print all the perfect numbers from 1-1000. It does not print any numbers to the console.
Code:

#include<iostream>
using namespace std;
int main()
{
    int num = 1, adder = 1, numChecker = 0;
    for(num = 1; num >= 1000; num++)
    {
        numChecker = 0;
        for(adder = 1; adder > num; adder++)
        {
            if(num % adder == 0)
            {
                numChecker += adder;
            }
        }
        if(num == numChecker)
        {
            cout << num << endl;
        }
    }
    return 0;
}

[wolle]

Check the for-loops.

If for example you want the variable num to take values from 1 up to (and including) 1000 you should do,

    for (num = 1; num <= 1000; num++)

[VictorN]

Well, I have edited your code t make it readable.
Now you could see that it prints something only if num == numChecker.
So try to debug your code step-by-step to see what goes wrong or non-expected.

I'd also recommend you to begin testing with some more trivial diapasons like 1-5, 1-10, 1-20, etc.

[2kaud]

Also note that within the range of an int, there are no odd perfect numbers (indeed currently there are no known odd perfect numbers at all!). So the starting value for the outer for loop could be 2 and not 1 and the value could be incremented by 2 rather than 1 (to generate even numbers).

Note also that 1 is always a divisor of an integer - so need not be tried. So numchecker could be initialised to 1 and the starting value for the inner for loop could be 2 and not 1.