Introduction to a simple example of simulating hashtable in js

This article mainly introduces simple examples of simulating hashtable in js. If you need some help, please refer to it.

The Code is as follows: 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;} 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. the code for _ hash [k] ;}} is as follows: // 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} else {this. objArr [key] = value; this. count ++; return true ;}/// whether or not this is included. contains = function (key) {return this. objArr. h AsOwnProperty (key);} // retrieving an item is equivalent to 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 Error // return ;}} // 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 invalid // ht. Clear (); // Clear alert (ht. Count );}