C++ program to check whether a number is Palindrome or not
Program to check whether a number is Palindrome or not
Here we will discuss how to check whether a number is palindrome or not using C++ Programming language.
A number is a Palindrome number if the reverse of the number and the numbers itself are equal i.e. if number and its reverse are same then the number is a palindrome number.
Example: Let’s take a number say 2876. Here the reverse of the number is 6782 which is not equal to the number so 2876 is not a palindrome number.
Let’s take another number say 12121. Here the reverse of the number is 12121 which is equal to the number, so 12121 is a Palindrome number.To check for palindrome number we will first reverse the number using a loop and then compare them number and its reverse using the if statement.
Let’s see how the code works:
- User gives an input.
- Input is stored in an int type variable say num.
- num is copied in another int type variable temp
- Now using a do while loop the reverse of num will be found.
- Modulus(%) of num is found with 10 and stored in an int type variable say digit.
digit = num%10;
- An int variable reverse(initialised at 0) is multiplied by 10 and digit is added to it and the result is stored in reverse itself.
reverse = (reverse*10) + digit;
- num is divided by 10 and the value is stored in num itself.
num /= 10;
- The loop works until num is not equal to 0.
- Now reverse will be compared with temp.
- If both are equal then the num is Palindrome
- Otherwise the num is not a Palindrome.
//Palindrome or not
using namespace std;
int num, digit, reverse = 0;
cout << "Enter a positive integer: ";
cin >> num;
int temp = num;
//loop to find reverse
digit = num % 10;
reverse = (reverse * 10) + digit;
num = num / 10;
} while (num != 0);
cout << "The reverse of "<< temp <<" is "<< reverse << endl;
//checking for palindrome
if (temp == reverse)
cout << "The number is a palindrome.";
cout << "The number is not a palindrome.";
Enter a positive integer: 12121
The reverse of 12121 is 12121
The number is a palindrome.