Need Help with Java HW!

[IvanSnipedYu]

IDK why my product is not coming out correctly.

 

The problem is: 

Write a program which asks for two integers a and b and displays the following output: • The sum of all numbers between [a, b] • The product of all even numbers between [a, b] • The sum of all squares between [a, b] Input Validation: a and b cannot be negative. Must validate using loop validation. Challenge: Solve the problem using only one loop.

 

The output is suppose to be:

Enter the values for a and b: 7 25

Sum of all numbers between 7 and 25: 304

Product of all even numbers between 7 and 25: 40874803200

Sum of all squares between 7 and 25: 5434

 

My solution is:
 

import java.util.Scanner;

public class HW05P01 {
	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		
		
		System.out.print("Enter 2 integers: ");
		int a = input.nextInt();
		int b = input.nextInt();
		
		int sum = 0;
		int product = 1;
		int sum2 = 0;
		int answer = 0;
		
				
		do{
			sum += a;
			if(a%2 == 0){
				product *= a;
			}
			sum2 += Math.pow(a, 2);
			++a;
		}while (a > 0 && b > 0 && a <= b);
		
		
		
		System.out.println("The sum of all the digits: " + sum);
		System.out.println("The product of all the even digits: " + product);
		System.out.println("The sum of all the squares: " + sum2);

	}
	
	
}

which for some reason gives me the wrong output for product.

[elpiop]

You're getting an overflow. The maximum value for an integer in Java is 2,147,483,647. Change product to a double or a long, which have higher maximum values. 

[IvanSnipedYu]

10 minutes ago, elpiop said:

You're getting an overflow. The maximum value for an integer in Java is 2,147,483,647. Change product to a double or a long. 

omg. I forgot about overflow's. Is there a way I can convert it back to standard form instead of scientific notation because i get 4.08748032E10 instead of 408748032.

[elpiop]

You can use printf(). 

 

System.out.printf("The product of all the even digits: %.0f",product);

 

This formats the number to 0 decimal places.

 

[IvanSnipedYu]

1 minute ago, elpiop said:

You can use printf(). 

 

System.out.printf("The product of all the even digits: %.0f",product);

 

This formats the number to 0 decimal places.

 

Thanks!

[elpiop]

Any time.