Get All Perfect Numbers In A Range Of Two Numbers

Program To Check Whether A Number Is A Perfect Number Or Not

using System;  
using System.Collections.Generic;  
using System.Linq;  
using System.Text;  
using System.Threading.Tasks;  
  
namespace PerfectNumberInRange  
{  
    class Program  
    {  
        static void Main(string[] args)  
        {  
            int startingNumber, endingNumbeer;  
            Console.WriteLine("Get All Perfect In Range of Between two Number");  
            Console.Write("Enter Starting Number : ");  
            startingNumber = int.Parse(Console.ReadLine());  
            Console.Write("Enter Ending Number : ");  
            endingNumbeer = int.Parse(Console.ReadLine());  
  
            Console.WriteLine("Below are the perfect number between " + startingNumber + " and " + endingNumbeer);  
               
            for (int i = startingNumber; i <= endingNumbeer; i++)  
            {  
                decimal sum = 0;  
                for (int j = 1; j < i; j++)  
                {  
                    if (i % j == 0)  
                        sum = sum + j;  
                }  
                if (sum == i)  
                    Console.WriteLine("\t" +i);  
            }  
  
            Console.ReadKey();  
        }  
    }  
}  

Output

• Here we get two inputs from the user, a starting number, and an ending number.
• Then we iterate the loop from the starting number to the ending number.
• In this loop iterate another loop from 1 to the value of the parent loop and declare a new variable called sum and assign zero to it.
• In child loop we modulate the parent loop value with the child loop value. If the value is equal to zero then add that value in the sum variable.
• After the child loop completes, check if the sum value and parent loop value both are equal or not. If both values are equal then this number is a perfect number.
• Then we use the Console.ReadKey() method to read any key from the console. By entering this line of code, the program will wait and not exit immediately. The program will wait for the user to enter any key before finally exiting. If you don't include this statement in the code, the program will exit as soon as it is run.