Abh*_*nav 1 javascript prototype last-modified getter-setter
我是JavaScript的新手.在使用给定的javascript时,我期望输出值为"123"; "测试1"; "456"和"test2",因为有两个实例.
但返回的值是"456";"test2"; "456"和"test2".
如果我更改setter以处理"this"(目前在代码中已经出现),问题就解决了.我无法理解为什么protype对象表现得很差.
我不想用这个声明变量,因为我希望变量是私有的,只能通过getter/setters方法访问.
<html>
<head>
<script type="text/javascript">
function Test(){
var name;
var id;
Test.prototype.setId = function(newId){
id = newId;
}
//this.id = function(newId){
Test.prototype.getId = function(newId){
return id;
}
Test.prototype.setName = function(newName){
name = newName;
}
//this.getName = function(newGuid){
Test.prototype.getName = function(newGuid){
return name;
}
}
function callme(){
var instance1 = new Test();
instance1.setId("123");
instance1.setName("test1");
var instance2 = new Test();
instance2.setId("456");
instance2.setName("test2");
alert(instance1.getId());
alert(instance1.getName());
alert(instance2.getId());
alert(instance2.getName());
}
</script>
</head>
<body>
<button onclick='callme()'> Test </button>
</body>
</html>
根据下面给出的Matt的建议,我已经改变了我的代码.但代码不适用于继承.我修改了代码如下.当前实现创建派生类型的对象并尝试调用基类的方法.
<html>
<head>
<script type="text/javascript">
(function () {
var stores = [];
var counter = 0;
Test = function () {
this.storeId = stores.length;
stores.push({});
}
Test.prototype.setGuid = function (newId) {
stores[this.storeId].id = newId;
}
Test.prototype.getGuid = function (newId) {
return stores[this.storeId].id;
}
Test.prototype.setName = function (newName) {
stores[this.storeId].name = newName;
}
Test.prototype.getName = function (newGuid) {
return stores[this.storeId].name;
}
})();
Derived.prototype = new Test();
Derived.prototype.constructor = Derived
function Derived(){
Test();//call to base class
//some additional method
}
function callme(){
var instance1 = new Derived();
instance1.setGuid("123");
instance1.setName("test1");
var instance2 = new Derived();
instance2.setGuid("456");
instance2.setName("test2");
alert(instance1.getName());
alert(instance1.getGuid());
alert(instance2.getName());
alert(instance2.getGuid());
}
</script>
</head>
<body>
<button onclick='callme()'> Test </button>
</body>
</html>
其次,stores当变量被清除(超出范围)时,我不确定从变量中清除内存.
您的房产是全球性的.您必须使用它this来引用实例的属性.
像这样修复你的代码:
function Test(){
this.name =''; // this only to show that the property exist,
// it doesn't change the behavior as you set it later
this.id='';
}
Test.prototype.setId = function(newId){
this.id = newId;
}
Test.prototype.getId = function(){
return this.id;
}
Test.prototype.setName = function(newName){
this.name = newName;
}
Test.prototype.getName = function(){
return this.name;
}
我解决了一些其他问题,其中包括你不应该声明参数的事实,getX因为你不需要它.