C++ Program to Reverse a Number

Write a C++ Program to reverse a number.

Example:

Input:  456
Output: 654

Input:  132
Output: 231

Input: 456

Output: 654

Input: 132

Output: 231

To reverse a number, we need to extract and append the last digit from the original number to its reverse rev = rev*10 + num%10.

We have to remove the last digit once it has been appended to the reverse string num = num/10.

So let’s write the C++ program.

#include <iostream>

using namespace std;

int main()
{
    int num;
    
    //Input a number
    cout << "Enter a Number: ";
    cin >> num;
    
    //Initialize rev with 0
    int rev=0;
    
    //Append digits of num from last to first
    while(num>0){
        rev = rev*10 + num%10;
        num = num/10;
    }
    
    cout << "Reverse: " << rev;
    return 0;
}

#include <iostream>

using namespace std;

int main()

{

int num;

//Input a number

cout << "Enter a Number: ";

cin >> num;

//Initialize rev with 0

int rev=0;

//Append digits of num from last to first

while(num>0){

rev = rev*10 + num%10;

num = num/10;

}

cout << "Reverse: " << rev;

return 0;

}

Output

Enter a Number: 243 Reverse: 342

If you have any doubts or suggestion then comment below.

Leave a Reply Cancel reply