Program to check Perfect Number in Java | AskTheCode

Java program to check Perfect Number using isPerfectNumber method | Java Programming Solution

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Problem:

An integer is said to be Perfect Number if the sum of its factors including 1 (but not the number itself ) is equal to the number itself.

For example, 6 is a perfect number because 6 = 1 + 2 + 3.

Write a method isPerfectNumber using the following signature that determines if parameter number is perfect number. Use this method in a main method that determine and prints all the perfect numbers between 1 and 1000.

public boolean isPerfectNumber (int number)

Output:

6

28

496

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Code:

import java.lang.*;

class PerfectNumber{
	public static void main (String[] args){
		PerfectNumber pn = new PerfectNumber();
		for (int i = 1; i <= 1000; i++) {
			boolean result = pn.isPerfectNumber(i);
			if (result == true)
				System.out.println(i);
		}
	}

	public boolean isPerfectNumber(int number){
		int sum = 0;
		for (int i = 1; i < number; i++) {
			if (number % i == 0)
				sum = sum + i;
		}

		if (sum == number)
        	return true;
 
    	return false;
	}
}