1 /**
 2  * Definition for singly-linked list.
 3  * function ListNode(val, next) {
 4  *     this.val = (val===undefined ? 0 : val)
 5  *     this.next = (next===undefined ? null : next)
 6  * }
 7  */
 8 /**
 9  * @param {ListNode} head
10  * @return {boolean}
11  */
12 var isPalindrome = function(head) {
13     let temp = [];
14     while(head) {
15         temp.push(head.val);
16         head = head.next;
17     }
18     return temp.join(‘‘) === temp.reverse().join(‘‘)
19 };