Day6.js

/*

// Write a function to determine whether a given string is a palindrome or not. A palindrome is a word, phrase,number, or other sequence of characters that reads the same forward and backward, ignoring spaces, punctuation, and
capitalization.

console.log (isPalindrome("A man, a plan, a canal, Panama") ); // Output: true
console.log (isPalindrome ("racecar")); // Output: true
console.log (isPalindrome("hello")); // Output: false

// Constraints:

The input string may contain letters, digits, spaces, punctuation, and special characters.
The function should be case-insensitive, meaning "Racecar" and "racecar" should be considered the same.
Ignore spaces, punctuation, and special characters when determining if a string is a palindrome.
The function should return true if the input string is a palindrome and false otherwise.

*/

const isPalindrome = (input) => {
  input = input.toLowerCase().replace(/\W/g, ""); // read NOTE below for reference
  inputSplit = input.split("");
  //   console.log(inputSplit);
  inputSplitLen = inputSplit.length;
  // console.log(inputSplitLen);
  for (let i = 0; i < inputSplitLen / 2; i++) {
    if (inputSplit[i] !== inputSplit[inputSplitLen - 1 - i]) {
      return false;
    }
  }
  return true;
};

console.log(isPalindrome("A man, a plan, a canal, Panama")); // Output: true
console.log(isPalindrome("racecar")); // Output: true
console.log(isPalindrome("hello")); // Output: false

/*


// Note

replace(/\W/g, "'): Uses the replace() method with a regular expression (/\W/g) to remove all non-word
characters from the string. 

Here:
// \W matches any non-word character (equivalent to [^a-zA-Z0-9_]).
// The g flag performs a global search, meaning it replaces all occurrences of non-word characters in the string.
// So, replace(/\W/g, "') replaces all non-word characters with an empty string, effectively removing them from the
string.


*/