First, briefly introduce some of the methods for attributes:
Enumeration of attributes:
A for/in loop is a way of traversing an object's properties. Such as
Copy Code code as follows:
var obj = {
Name: ' Obj1 ',
AGE:20,
Height: ' 176cm '
}
var str = ';
for (var name in obj)
{
str + = name + ': ' + obj[name] + ' \ n ';
}
alert (str);
Output is: name:obj1
Age:20
height:176cm
Check to see if the property exists:
The in operator can be used to test whether a property exists.
Copy Code code as follows:
This.containskey = function (key)
{
Return (key in entry);
}
Delete attribute
Use the delete operator to delete an object's properties. A property that is deleted using the delete for/in will not enumerate the property, and the in operator will not detect the property.
Delete Entry[key];
Delete Obj.name;
The following is the implementation of the hash table (hashtable) JS:
Copy Code code as follows:
function HashTable ()
{
var size = 0;
var entry = new Object ();
This.add = function (key, value)
{
if (!this.containskey (key))
{
Size + +;
}
Entry[key] = value;
}
This.getvalue = function (key)
{
return This.containskey (key)? Entry[key]: null;
}
This.remove = function (key)
{
if (This.containskey (key) && (delete entry[key))
{
Size--;
}
}
This.containskey = function (key)
{
Return (key in entry);
}
This.containsvalue = function (value)
{
For (Var prop in entry)
{
if (entry[prop] = = value)
{
return true;
}
}
return false;
}
This.getvalues = function ()
{
var values = new Array ();
For (Var prop in entry)
{
Values.push (Entry[prop]);
}
return values;
}
This.getkeys = function ()
{
var keys = new Array ();
For (Var prop in entry)
{
Keys.push (prop);
}
return keys;
}
This.getsize = function ()
{
return size;
}
This.clear = function ()
{
size = 0;
Entry = new Object ();
}
}
Test:
Code
Copy Code code as follows:
<! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">
<title>HashTable</title>
<script type= "Text/javascript" src= "/js/jquery.js" ></script>
<script type= "Text/javascript" src= "/js/hashtable.js" ></script>
<script type= "Text/javascript" >
function MyObject (name)
{
THIS.name = name;
this.tostring = function () {
return this.name;
}
}
$ (function () {
var map = new HashTable ();
Map.add ("A", "1");
Map.add ("B", "2");
Map.add ("A", "5");
Map.add ("C", "3");
Map.add ("A", "4");
var arraykey = new Array ("1", "2", "3", "4");
var arrayvalue = new Array ("A", "B", "C", "D");
Map.add (Arraykey,arrayvalue);
var value = Map.getvalue (Arraykey);
var object1 = new MyObject ("Small 4");
var object2 = new MyObject ("small 5");
Map.add (Object1, "small 4");
Map.add (Object2, "small 5");
$ (' #console '). HTML (Map.getkeys (). Join (' | ') + ' <br> ');
})
</script>
<body>
<div id= "Console" ></div>
</body>
JavaScript Hashtable Implementation code
Http://www.jb51.net/article/20372.htm
