Program of reverse of a number in c,java,python

Algorithm

algorithm to reverse a number can be described using the following steps:

1. Initialize a variable to store the reversed number, let’s call it reversedNumber, and set it to 0.
2. Extract the rightmost digit of the given number by using the modulo operator % with 10. Let’s call this digit remainder.
3. Multiply the current reversedNumber by 10 and add the remainder to it. This step appends the remainder digit to the reversed number.
4. Divide the given number by 10, discarding the rightmost digit. This step removes the rightmost digit from the given number.
5. Repeat steps 2 to 4 until the given number becomes 0.
6. The final value of reversedNumber will be the reversed form of the original number.

C

#include <stdio.h>

int reverseNumber(int number) {
    int reversedNumber = 0;

    while (number != 0) {
        int remainder = number % 10;
        reversedNumber = reversedNumber * 10 + remainder;
        number /= 10;
    }

    return reversedNumber;
}

int main() {
    int number;

    printf("Enter a number: ");
    scanf("%d", &number);

    int reversedNumber = reverseNumber(number);

    printf("Reversed number: %d\n", reversedNumber);

    return 0;
}

the reverseNumber() function takes an integer as input and reverses it. It uses a while loop to extract the digits of the number one by one and builds the reversed number by multiplying the current reversed number by 10 and adding the extracted digit. Finally, the reversed number is returned.

In the main() function, the user is prompted to enter a number. The scanf() function is used to read the input and store it in the number variable. Then, the reverseNumber() function is called, passing the number as an argument. The reversed number is stored in the reversedNumber variable and printed using printf().

C++

#include <iostream>

int reverseNumber(int number) {
    int reversedNumber = 0;

    while (number != 0) {
        int remainder = number % 10;
        reversedNumber = reversedNumber * 10 + remainder;
        number /= 10;
    }

    return reversedNumber;
}

int main() {
    int number;

    std::cout << "Enter a number: ";
    std::cin >> number;

    int reversedNumber = reverseNumber(number);

    std::cout << "Reversed number: " << reversedNumber << std::endl;

    return 0;
}

we use similar logic as the C program to reverse the number. The reverseNumber() function takes an integer as input, reverses it, and returns the reversed number.

In the main() function, the user is prompted to enter a number using std::cout. The input is then read using std::cin and stored in the number variable. The reverseNumber() function is called, passing the number as an argument. The reversed number is stored in the reversedNumber variable.

Finally, the reversed number is printed to the console using std::cout along with std::endl.

java

import java.util.Scanner;

public class ReverseNumber {
    public static int reverseNumber(int number) {
        int reversedNumber = 0;

        while (number != 0) {
            int remainder = number % 10;
            reversedNumber = reversedNumber * 10 + remainder;
            number /= 10;
        }

        return reversedNumber;
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.print("Enter a number: ");
        int number = scanner.nextInt();

        int reversedNumber = reverseNumber(number);

        System.out.println("Reversed number: " + reversedNumber);
    }
}

we define a class called ReverseNumber. It has a reverseNumber() method that takes an integer as input, reverses it, and returns the reversed number.

In the main() method, we create a Scanner object to read user input. The user is prompted to enter a number using System.out.print(), and the input is read using scanner.nextInt() and stored in the number variable.

Then, we call the reverseNumber() method, passing the number as an argument. The reversed number is stored in the reversedNumber variable.

Finally, we print the reversed number to the console using System.out.println().

Python

def reverse_number(number):
    reversed_number = 0

    while number != 0:
        remainder = number % 10
        reversed_number = reversed_number * 10 + remainder
        number //= 10

    return reversed_number

number = int(input("Enter a number: "))
reversed_number = reverse_number(number)

print("Reversed number:", reversed_number)

we define a function called reverse_number() that takes an integer as input, reverses it, and returns the reversed number.

We use a while loop to extract the digits of the number one by one. Inside the loop, we calculate the remainder by using the modulo operator % with 10. We then update the reversed_number variable by multiplying it by 10 and adding the remainder. Finally, we update the number by using integer division // with 10 to remove the last digit.

In the main part of the code, we prompt the user to enter a number using the input() function and convert it to an integer using int(). We then call the reverse_number() function, passing the number as an argument. The reversed number is stored in the reversed_number variable.