27.C Program to Check Whether a Number is Palindrome or Not

C Program to Check Whether a Number is Palindrome or Not

This program reverses an integer (entered by the user) using while loop. Then, if statement is used to check whether the reversed number is equal to the original number or not.

To understand this example, you should have the knowledge of following C programming topics:

• C Programming Operators
• C if, if...else and Nested if...else Statement
• C programming while and do...while Loop

An integer is a palindrome if the reverse of that number is equal to the original number.

Example: Program to Check Palindrome

#include <stdio.h>
int main()
{
    int n, reversedInteger = 0, remainder, originalInteger;

    printf("Enter an integer: ");
    scanf("%d", &n);

    originalInteger = n;

    // reversed integer is stored in variable 
    while( n!=0 )
    {
        remainder = n%10;
        reversedInteger = reversedInteger*10 + remainder;
        n /= 10;
    }

    // palindrome if orignalInteger and reversedInteger are equal
    if (originalInteger == reversedInteger)
        printf("%d is a palindrome.", originalInteger);
    else
        printf("%d is not a palindrome.", originalInteger);
    
    return 0;
}

Output

Enter an integer: 1001
1001 is a palindrome.

Check out these related examples:

• C Program to Count Number of Digits in an Integer
• C Program to Print an Integer (Entered by the User)
• C Program to Compute Quotient and Remainder