学习数据结构的记录
列表是一种数据项构成的有限序列，即按照一定的线性顺序，排列而成的数据项的集合，在这种数据结构上进行的基本操作包括对元素的的查找，插入，和删除
列表的两种主要表现是数组和链表，栈和队列是两种特殊类型的列表
迭代器（iterator）有时又称游标（cursor）是程序设计的软件设计模式，可在容器（container，例如链表或阵列）上遍访的接口，设计人员无需关心容器的内容
front,end,prev,next使用了迭代器的原理
'use strict'
function List(){
this.size = 0;
this.pos = 0;
this.data = [];
this.clear = clear;
this.find = find;
this.toString = toString;
this.insert = insert;
this.append = append;
this.remove = remove;
this.front = front;
this.end = end;
this.prev = prev;
this.next = next;
this.length = length;
this.currPos = currPos;
this.moveTo = moveTo;
this.getElement = getElement;
this.contains = contains;
};
function append(element){
this.data[this.size++] = element;
}
function find(element){
for(var i = 0; i < this.data.length; i++){
if(this.data[i] == element){
return i;
}
}
return -1;
}
function remove(element){
var foundAt = this.find(element);
if(foundAt > -1){
this.data.splice(foundAt,1);
--this.size;
return true;
}
return false;
}
function length(){
return this.size;
}
function toString(){
return this.data;
}
function insert(element, after){
var insertPos = this.find(after);
if(insertPos > -1){
this.data.splice(insertPos+1, 0, element);
++this.size;
return true;
}
return false;
}
function clear(){
delete this.data;
this.data.length = 0;
this.size = this.pos = 0;
}
/*判断查询元素是否在列表内*/
function contains(element){
for (var i = 0; i < this.data.length; i++) {
if(this.data[i] == element){
return true;
}
}
return false
}
/*移动到第一个元素*/
function front(){
this.pos = 0;
}
/*移动到最后一个元素*/
function end(){
this.pos = this.size - 1;
}
function prev(){
if(this.pos > 0){
--this.pos;
}
}
function next(){
if(this.pos < this.size -1){
++this.pos;
}
}
function currPos(){
return this.pos;
}
function getElement(){
return this.data[this.pos];
} var names = new List();
names.append('lily');
names.append('tom');
names.append('king');
names.append('lihua');
names.append('lisi'); names.front();
console.log(names.getElement()) //lily names.next();
console.log(names.getElement()) //tom var asd = names.find('king')
console.log(asd) // names.insert('jacks', 'king')
console.log(names.data) //["lily", "tom", "king", "jacks", "lihua", "lisi"]