Reverse Any Integer Number | Java Programs

Output:

*** Reverse An Integer ***

Enter any number : 1234567

The Original Number is: 1234567
Reversed Number is   : 7654321

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Solution:

import java.util.Scanner;

class ReverseAnInteger {

    public static void main(String[] args) {
        System.out.println("*** Reverse An Integer ***" + "\n");
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter any number : ");
        int num = scanner.nextInt();
        System.out.println("\nThe Original Number is: " + num);
        int is_positive = 1;
        if (num < 0) {
            is_positive = -1;
            num = -1 * num;
        }
        int sum = 0;
        while (num > 0) {
            int r = num % 10;

            int maxDiff = Integer.MAX_VALUE - sum * 10;
            if (sum > Integer.MAX_VALUE / 10 || r > maxDiff) {
                System.out.println("Wrong number");
            }

            sum = sum * 10 + r;
            num /= 10;
        }
        int reversed = is_positive * sum;
        System.out.println("Reversed Number is   : " + reversed);
    }
}