A simple example of js simulating hashtable_javascript skills

复制代码 代码如下:

function Hashtable()//自定义hashtable
{
    this._hash = new Object();
    this.add = function(key, value) {
        if (typeof (key) != "undefined") {
            if (this.contains(key) == false) {
                this._hash[key] = typeof (value) == "undefined" ? null : value;
                return true;
            } else {
                return false;
            }
        } else {
            return false;
        }
    }
    this.remove = function(key) { delete this._hash[key]; }
    this.count = function() { var i = 0; for (var k in this._hash) { i ; } return i; }
    this.items = function(key) { return this._hash[key]; }
    this.contains = function(key) { return typeof (this._hash[key]) != "undefined"; }
    this.clear = function() { for (var k in this._hash) { delete this._hash[k]; } }
}

复制代码 代码如下:

//js hash table
function HashTable() {

this.ObjArr = {};

this.Count = 0;

//Add
this.Add = function(key, value) {
if (this.ObjArr.hasOwnProperty(key)) {
return false; //If the key already exists, do not add it
}
else {
this.ObjArr[key] = value;
this.Count ;
return true;
}
}

//Whether it contains an item
this.Contains = function(key) {
return this.ObjArr.hasOwnProperty(key);
}

//Getting an item is equivalent to this.ObjArr[key]
this.GetValue = function(key) {
if (this.Contains(key)) {
return this. ObjArr[key];
                                                                                                                                                                                                                                                                 🎜> }

//Remove
this.Remove = function(key) {
if (this.Contains(key)) {
delete this.ObjArr[key];

this.Count- -;

}
}

// Clear
this.Clear = function() {
this.ObjArr = {}; this.Count = 0;
}

}

Test code:
//Employee
function employee(id, userName) {
this.id = id;
this.userName = userName;
}

function test() {

var ht = new HashTable();
var tmpEmployee = null;

for (var i = 1; i < 6; i ) {

tmpEmployee = new employee(i, "Employee_" i);

ht.Add(i, tmpEmployee);

}
for (var i = 1; i <= ht.Count; i ) {
alert(ht.GetValue(i ).userName); //Actually equivalent to ht.ObjArr[i].userName
//alert(ht.ObjArr[i].userName);
}
ht.Remove(1);
alert(ht.Contains(1)); //false
alert(ht.Contains(2)); //true
//alert(ht.GetValue(1)); //Exception
var result = ht.GetValue(2);
if (result != null) {
alert("Employee Id:" result.id ";UserName:" result.userName);
}
ht.Add(2, "This key already exists!"); //Add is invalid
//ht.Clear(); //Clear
alert(ht.Count);

}