palindrome strings examples

Example 1: reads the string in then determines if the string is a palindrome.

#include <iostream>
using namespace std;
 
// Iterative function to check if given string is a palindrome or not
bool isPalindrome(string str)
{
    int low = 0;
    int high = str.length() - 1;
 
    while (low < high)
    {
        // if mismatch happens
        if (str[low] != str[high])
            return false;
 
        low++;
        high--;
    }
 
    return true;
}
 
int main()
{
    string str = "XYXYX";
 
    if (isPalindrome(str))
        cout << "Palindrome";
    else
        cout << "Not Palindrome";
 
    return 0;
}

Example 2: palindrome

function isPalindrome(sometext) {
  var replace = /[.,'!?\- \"]/g; //regex for what chars to ignore when determining if palindrome
  var text = sometext.replace(replace, '').toUpperCase(); //remove toUpperCase() for case-sensitive
  for (var i = 0; i < Math.floor(text.length/2) - 1; i++) {
    if(text.charAt(i) == text.charAt(text.length - 1 - i)) {
      continue;
    } else {
      return false;
    }
  }
  return true;
}
//EDIT: found this on https://medium.com/@jeanpan/javascript-splice-slice-split-745b1c1c05d2
//, it is much more elegant:
function isPalindrome(str) {
  return str === str.split('').reverse().join(''); 
}
//you can still add the regex and toUpperCase() if you don't want case sensitive

Example 3: palindrome

#include <stdio.h>
int main() {
    int n, reversedN = 0, remainder, originalN;
    printf("Enter an integer: ");
    scanf("%d", &n);
    originalN = n;

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

    // palindrome if orignalN and reversedN are equal
    if (originalN == reversedN)
        printf("%d is a palindrome.", originalN);
    else
        printf("%d is not a palindrome.", originalN);

    return 0;
}

Example 4: reads the string in then determines if the string is a palindrome.

#include <iostream>
using namespace std;
 
// Recursive function to check if str[low..high] is a palindrome or not
bool isPalindrome(string str, int low, int high)
{
    // base case
    if (low >= high)
        return true;
 
    // return false if mismatch happens
    if (str[low] != str[high])
        return false;
 
    // move to next the pair
    return isPalindrome(str, low + 1, high - 1);
}
 
int main()
{
    string str = "XYBYBYX";
    int len = str.length();
 
    if (isPalindrome(str, 0, len - 1))
        cout << "Palindrome";
    else
        cout << "Not Palindrome";
 
    return 0;
}