How do you check if a given String is Palindrome or not? code example

Example 1: check if palindrome

function isPalindrome(str) {
  str = str.toLowerCase();
  return str === str.split("").reverse().join("");
}

Example 2: check palindrome

bool isPlaindrome(string s)
	{
	   int i=0;
	   int j=s.length()-1;
	   while(i<j)
	   {
	       if(s[i]==s[j])
	       {i++;
	   j--;}
	   else break;
	   }
	   if (i==j || i>j) return 1;
	   else return 0;
	}