循环时javascript最长的回文

Question

如何返回＆＃39;＆＃39;什么时候叫一个字母？

＆＃13;

＆＃13;

function isPalindrome(s) {
  var rev = s.split("").reverse().join("");
  return s == rev;
}

function longestP(string) {     
  var maxP = ''; var maxL = 0;  
  var i = 0;
  while(i < string.length) {   
    length = 1;
    while(i+length <= string.length) {     
      substring = string.slice(i,length);
      
      if(isPalindrome(substring)) {
        if(substring.length > maxL) {
          maxL = substring.length;
          maxP = substring
        }
      }
      length = length +1
    }
    i++
  }
  return maxP
}

console.log(longestP('abba'))
console.log(longestP('a'))

＆＃13;

＆＃13;

＆＃13;