function Hashtable()//Custom 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]; } }
}
//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 or not it contains an item
this.Contains = function(key) {
return this.ObjArr.hasOwnProperty(key);
}
//So if I take a term that's the same thing as this.objarr [key]
this.GetValue = function(key) {
if (this.Contains(key)) {
return this.ObjArr[key];
}
else {
throw Error("Hashtable not cotains the key: " + String(key)); //Script errors
//return;
}
}
// remove
this.Remove = function(key) {
if (this.Contains(key)) {
delete this.ObjArr[key];
this.Count--;
}
}
// empty
this.Clear = function() {
this.ObjArr = {}; this.Count = 0;
}
}
The test code :
// employees
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); //This is 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)); // abnormal
var result = ht.GetValue(2);
if (result != null) {
alert("Employee Id:" + result.id + ";UserName:" + result.userName);
}
ht.Add(2, " This one key existing !"); //The Add is invalid
//ht.Clear(); // empty
alert(ht.Count);
}