Check Palindrome String C Program

Check Palindrome String C Program – Input a string and check whether this string entered by the user is a Palindrome or Not.

Check Palindrome String C Programming

Source Code

#include <stdio.h>
#include <string.h>
 
int main()
{
    char str[100];  
    int i,size,palindrome=1;
 
    printf("Enter  the string : ");
    gets(str);
    size=strlen(str);

    for(i=0;i<size/2;i++)  
    {
    	if(str[i]!=str[size-i-1])
    	{
		palindrome=0;
		break;
		}
		

 	}
 	if(palindrome==1)
 	    printf("%s string is palindrome",str);
    else
        printf("%s string is not palindrome",str);

 	     
    return 0;
}

Detailed Explanation of Source Code

Let’s go through the given C program line by line and provide an explanation for each line:

These are preprocessor directives that include the necessary header files for the program. <stdio.h> is required for input/output operations, and <string.h> is needed for string manipulation functions.

This is the main function of the program. It declares a character array str of size 100 to store the input string. It also declares integer variables i, size, and palindrome, where palindrome is initialised to 1.

This line prompts the user to enter a string and stores it in the str array using the gets() function. Note that gets() is generally discouraged to use due to potential buffer overflow issues. A safer alternative would be to use fgets().

This line calculates the length of the string entered by the user using the strlen() function and assigns it to the size variable.

This for loop checks if the string is a palindrome. It iterates from the beginning of the string (i = 0) up to half its length (size / 2). It compares the character at position i with the character at position size - i - 1 (which is the corresponding character from the end of the string). If there is any mismatch, the palindrome variable is set to 0, indicating that the string is not a palindrome. The loop is also terminated using break.

This if-else statement checks the value of the palindrome variable. If it is 1, it means the string is a palindrome, so the corresponding message is printed. Otherwise, if palindrome is 0, the string is not a palindrome, and the respective message is printed.

This statement terminates the main() function and returns 0, indicating successful execution of the program.

Output

Enter the string : mom
mom string is palindrome
——————————–

Output 2:

Enter the string : father
father string is not palindrome

Palindrome string checking Program – Summary: This C program checks whether a given string is a palindrome or not. It takes a string as input, compares the characters from the beginning and end of the string, and determines if it is a palindrome. The program then outputs whether the string is a palindrome or not.