JS栈stack类的实现与使用方法示例

/使用栈stack类的实现/
function stack() {
  this.dataStore = [];//保存栈内元素，初始化为一个空数组
  this. = 0;//栈顶位置，初始化为0
  this.push = push;//入栈
  this.pop = pop;//出栈
  this.peek = peek;//查看栈顶元素
  this.clear = clear;//清空栈
  this.length = length;//栈内存放元素的个数
}
function push(element){
  this.dataStore[this.++] = element;
}
function pop(){
  return this.dataStore[--this.];
}
function peek(){
  return this.dataStore[this.-1];
}
function clear(){
  this. = 0;
}
function length(){
  return this.;
}
/测试stack类的实现/
var s = new stack();
s.push("aa");
s.push("bb");
s.push("");
console.log(s.length());//3
console.log(s.peek());//
var popped = s.pop();
console.log(popped);//
console.log(s.peek());//bb