C Program to Check Palindrome Number

Posted in C Tutorial

Updated on Oct 06, 2024

By Mari Selvan

👁️ 241 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In the realm of programming, tasks involving numbers often include checking for special properties. One interesting property is whether a number is a palindrome.

A palindrome number reads the same backward as forward.

In this tutorial, we will explore a C program designed to check whether a given number is a palindrome.

The program involves reversing the digits of the number and comparing it with the original number

📄 Example

Let's delve into the C code that accomplishes this task.

isPalindrome.c

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#include <stdio.h>

// Function to check if a number is a palindrome
int isPalindrome(int number) {
  int originalNumber = number;
  int reversedNumber = 0, remainder;

  // Reverse the digits of the number
  while (number != 0) {
    remainder = number % 10;
    reversedNumber = reversedNumber * 10 + remainder;
    number /= 10;
  }

  // If the reversed number is equal to the original number, it is a palindrome
  return originalNumber == reversedNumber;
}

// Driver program
int main() {
  // Replace this value with the number you want to check
  int number = 121;

  // Call the function to check if the number is a palindrome
  if (isPalindrome(number))
    printf("%d is a palindrome number.\n", number);
  else
    printf("%d is not a palindrome number.\n", number);

  return 0;
}

💻 Testing the Program

To test the program with different numbers, modify the value of number in the main program.

Output

121 is a palindrome number.

Compile and run the program to check if the specified number is a palindrome.

🧠 How the Program Works

The program defines a function isPalindrome that takes an integer number as input and returns 1 (true) if the number is a palindrome, and 0 (false) otherwise.
Inside the main program, replace the value of number with the desired number you want to check.
The program calls the isPalindrome function and prints the result.

📏 Between the Given Range

Let's delve into the C code that checks for palindrome numbers in the range 100 to 200.

isPalindrome.c

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#include <stdio.h>

// Function to check if a number is palindrome
int isPalindrome(int num) {
  int originalNum = num;
  int reversedNum = 0, remainder;

  while (num != 0) {
    remainder = num % 10;
    reversedNum = reversedNum * 10 + remainder;
    num /= 10;
  }

  return originalNum == reversedNum;
}

// Driver program
int main() {
  printf("Palindrome Numbers in the range 100 to 200:\n");

  for (int i = 100; i <= 200; ++i) {
    if (isPalindrome(i)) {
      printf("%d ", i);
    }
  }

  printf("\n");

  return 0;
}

💻 Testing the Program

Output

Palindrome Numbers in the range 100 to 200:
101 111 121 131 141 151 161 171 181 191

Run the program to check for palindrome numbers in the specified range.

🧠 How the Program Works

The program defines a function isPalindrome that checks if a given number is a palindrome.
Inside the function, it uses a while loop to reverse the digits of the number and compares the original number with its reversed form.
The main function tests the palindrome check for numbers in the range 100 to 200 and prints the palindrome numbers.