JavaScript栈的实现和回文判断

JavaScript栈的实现：

function Stack() {
  this.dataStore = [];
  this.top = 0;
  this.push = function (element) {
    this.dataStore[this.top++] = element;
  };
  this.pop = function () {
    return this.dataStore[--this.top];
  };
  this.peek = function () {
    return this.dataStore[this.top - 1]
  };
  this.length = function () {
    return this.top;
  };
  this.clear = function () {
    this.top = 0;
  };
}

Stack实现回文判断：

回文：一个单词、短语或数字，从前往后写和从后往前写都是一样的

function isPalindrome(word) {
  if (word === "")return true;
  if (!word)return false;
  var s = new Stack;
  var len = word.length, curr_index = 0;
  while (curr_index < len) {
    s.push(word[curr_index++]);
  }
  var newWord = '';
  while (s.top != 0) {
    newWord += s.pop();
  }
  return newWord == word;
}

console.log("abcd is Palindrome : " + isPalindrome("abcd"));
console.log("abcdcba is Palindrome : " + isPalindrome("abcdcba"));