类的JavaScript实例
假设我有一个函数：类的JavaScript实例,javascript,Javascript,假设我有一个函数： function Control(value){ var self=this; self.param1=value; self.param2=value.text; } 是否可以在JavaScript中获取该函数创建的所有实例？否 事实上，您只能触摸有显式引用的对象* *该安全模型不适用于全局对象的JavaScript。否 事实上，您只能触摸有显式引用的对象* *该安全模型不适用于全局对象的JavaScript。只需将其存储在全局数组中即可。将类似于
function Control(value){
var self=this;
self.param1=value;
self.param2=value.text;
}
*该安全模型不适用于全局对象的JavaScript。只需将其存储在全局数组中即可。将类似于一些静态模式
var controls = [] ; //Global array
function Control(value){
var self = this;
self.param1=value;
self.param2=value.text;
controls.push(self);
}
只需将其存储在全局数组中。将类似于一些静态模式
var controls = [] ; //Global array
function Control(value){
var self = this;
self.param1=value;
self.param2=value.text;
controls.push(self);
}
如果不修改该类，您将无能为力。如果可以修改，只需保留对所构造的每个实例的引用：
function Control(value){
Control.instances = Control.instances || [];
Control.instances.push(this);
var self=this;
self.param1=value;
self.param2=value.text;
}
// In case you are worried about garbage collection
Control.prototype.destroy = function() {
var index = Control.instances.indexOf(this);
Control.instances.splice(index, 1);
}
// Usage:
var x = new Control();
var y = new Control();
// do stuff with x and y
console.log('There are ' + Control.instances.length + ' instances of Control');
// all done with x and y
x.destroy();
x = null;
y.destroy();
y = null;
// no more references to the two instances, they can be garbage collected
不过，请注意，您将阻止垃圾收集器释放任何未调用destroy（）的实例的内存。如果不修改该类，您将无能为力。如果可以修改，只需保留对所构造的每个实例的引用：
function Control(value){
Control.instances = Control.instances || [];
Control.instances.push(this);
var self=this;
self.param1=value;
self.param2=value.text;
}
// In case you are worried about garbage collection
Control.prototype.destroy = function() {
var index = Control.instances.indexOf(this);
Control.instances.splice(index, 1);
}
// Usage:
var x = new Control();
var y = new Control();
// do stuff with x and y
console.log('There are ' + Control.instances.length + ' instances of Control');
// all done with x and y
x.destroy();
x = null;
y.destroy();
y = null;
// no more references to the two instances, they can be garbage collected
但是请注意，您将阻止垃圾收集器释放任何未调用destroy（）的实例的内存。正如@Ian在其评论中建议的那样，您可以这样做：
// global are bad though!
var controlInstances = [];
function Control(value){
// track instances
controlInstances.push(this)
this.param1 = value;
thsi.param2 = value.text;
}
正如@Ian在他的评论中所建议的，你可以这样做：
// global are bad though!
var controlInstances = [];
function Control(value){
// track instances
controlInstances.push(this)
this.param1 = value;
thsi.param2 = value.text;
}
我在我的一个项目中使用了类似的方法，因为我需要为所有实例调用一个方法
function Person(firstname, lastname) {
var self = this; // For reference to "this"
this.firstname = firstname;
this.lastname = lastname;
document.addEventListener( "event/person", function( event ) {
var params = event.detail.params;
Person.prototype[ params.method ].call(self);
// Take params: params.params => ["param1", "param2", "param3"]
});
}
Person.prototype.toString = function() {
console.log("Firstname: " + this.firstname + " Lastname: " + this.lastname);
};
Person.prototype.callAll = function( params ) {
document.dispatchEvent( new CustomEvent( "event/person", {
detail: {
"params": params
}
}));
};
var a = new Person("Gabriel", "Gatu");
var b = new Person("Marco", "Giovannini");
Person.prototype.callAll({
method: "toString",
params: ["param1", "param2", "param3"]
});
function Person(firstname, lastname) {
var self = this; // For reference to "this"
this.firstname = firstname;
this.lastname = lastname;
document.addEventListener( "event/person", function( event ) {
var params = event.detail.params;
Person.prototype[ params.method ].call(self);
// Take params: params.params => ["param1", "param2", "param3"]
});
}
Person.prototype.toString = function() {
console.log("Firstname: " + this.firstname + " Lastname: " + this.lastname);
};
Person.prototype.callAll = function( params ) {
document.dispatchEvent( new CustomEvent( "event/person", {
detail: {
"params": params
}
}));
};
var a = new Person("Gabriel", "Gatu");
var b = new Person("Marco", "Giovannini");
Person.prototype.callAll({
method: "toString",
params: ["param1", "param2", "param3"]
});
p、 对不起，英语不好……：） 我在我的一个项目中使用了类似的方法，因为我需要为所有实例调用一个方法
function Person(firstname, lastname) {
var self = this; // For reference to "this"
this.firstname = firstname;
this.lastname = lastname;
document.addEventListener( "event/person", function( event ) {
var params = event.detail.params;
Person.prototype[ params.method ].call(self);
// Take params: params.params => ["param1", "param2", "param3"]
});
}
Person.prototype.toString = function() {
console.log("Firstname: " + this.firstname + " Lastname: " + this.lastname);
};
Person.prototype.callAll = function( params ) {
document.dispatchEvent( new CustomEvent( "event/person", {
detail: {
"params": params
}
}));
};
var a = new Person("Gabriel", "Gatu");
var b = new Person("Marco", "Giovannini");
Person.prototype.callAll({
method: "toString",
params: ["param1", "param2", "param3"]
});
function Person(firstname, lastname) {
var self = this; // For reference to "this"
this.firstname = firstname;
this.lastname = lastname;
document.addEventListener( "event/person", function( event ) {
var params = event.detail.params;
Person.prototype[ params.method ].call(self);
// Take params: params.params => ["param1", "param2", "param3"]
});
}
Person.prototype.toString = function() {
console.log("Firstname: " + this.firstname + " Lastname: " + this.lastname);
};
Person.prototype.callAll = function( params ) {
document.dispatchEvent( new CustomEvent( "event/person", {
detail: {
"params": params
}
}));
};
var a = new Person("Gabriel", "Gatu");
var b = new Person("Marco", "Giovannini");
Person.prototype.callAll({
method: "toString",
params: ["param1", "param2", "param3"]
});
p、 对不起，英语不好……：） 我在我的一个项目中使用了类似的方法，因为我需要为所有实例调用一个方法
function Person(firstname, lastname) {
var self = this; // For reference to "this"
this.firstname = firstname;
this.lastname = lastname;
document.addEventListener( "event/person", function( event ) {
var params = event.detail.params;
Person.prototype[ params.method ].call(self);
// Take params: params.params => ["param1", "param2", "param3"]
});
}
Person.prototype.toString = function() {
console.log("Firstname: " + this.firstname + " Lastname: " + this.lastname);
};
Person.prototype.callAll = function( params ) {
document.dispatchEvent( new CustomEvent( "event/person", {
detail: {
"params": params
}
}));
};
var a = new Person("Gabriel", "Gatu");
var b = new Person("Marco", "Giovannini");
Person.prototype.callAll({
method: "toString",
params: ["param1", "param2", "param3"]
});
function Person(firstname, lastname) {
var self = this; // For reference to "this"
this.firstname = firstname;
this.lastname = lastname;
document.addEventListener( "event/person", function( event ) {
var params = event.detail.params;
Person.prototype[ params.method ].call(self);
// Take params: params.params => ["param1", "param2", "param3"]
});
}
Person.prototype.toString = function() {
console.log("Firstname: " + this.firstname + " Lastname: " + this.lastname);
};
Person.prototype.callAll = function( params ) {
document.dispatchEvent( new CustomEvent( "event/person", {
detail: {
"params": params
}
}));
};
var a = new Person("Gabriel", "Gatu");
var b = new Person("Marco", "Giovannini");
Person.prototype.callAll({
method: "toString",
params: ["param1", "param2", "param3"]
});
p、 对不起，英语不好……：）再见 我在我的一个项目中使用了类似的方法，因为我需要为所有实例调用一个方法
function Person(firstname, lastname) {
var self = this; // For reference to "this"
this.firstname = firstname;
this.lastname = lastname;
document.addEventListener( "event/person", function( event ) {
var params = event.detail.params;
Person.prototype[ params.method ].call(self);
// Take params: params.params => ["param1", "param2", "param3"]
});
}
Person.prototype.toString = function() {
console.log("Firstname: " + this.firstname + " Lastname: " + this.lastname);
};
Person.prototype.callAll = function( params ) {
document.dispatchEvent( new CustomEvent( "event/person", {
detail: {
"params": params
}
}));
};
var a = new Person("Gabriel", "Gatu");
var b = new Person("Marco", "Giovannini");
Person.prototype.callAll({
method: "toString",
params: ["param1", "param2", "param3"]
});
function Person(firstname, lastname) {
var self = this; // For reference to "this"
this.firstname = firstname;
this.lastname = lastname;
document.addEventListener( "event/person", function( event ) {
var params = event.detail.params;
Person.prototype[ params.method ].call(self);
// Take params: params.params => ["param1", "param2", "param3"]
});
}
Person.prototype.toString = function() {
console.log("Firstname: " + this.firstname + " Lastname: " + this.lastname);
};
Person.prototype.callAll = function( params ) {
document.dispatchEvent( new CustomEvent( "event/person", {
detail: {
"params": params
}
}));
};
var a = new Person("Gabriel", "Gatu");
var b = new Person("Marco", "Giovannini");
Person.prototype.callAll({
method: "toString",
params: ["param1", "param2", "param3"]
});
p、 对不起，英语不好……：）再见 我能想到的唯一简单的方法是在某个全局数组中存储对任何创建的
控件类的引用。您可以在控件
构造函数（上面的函数）中进行存储。据我所知，没有这样的事情。您需要有自己的机制来保存Control class.nope的所有实例（而不需要自己跟踪它们）。否则，垃圾收集器就不可能存在。可能的重复也请注意JavaScript中没有类。我能想到的唯一简单的方法是在某个全局数组中存储对任何创建的控件类的引用。您可以在控件
构造函数（上面的函数）中进行存储。据我所知，没有这样的事情。您需要有自己的机制来保存Control class.nope的所有实例（而不需要自己跟踪它们）。否则，垃圾收集器将不存在。的可能副本还请注意JavaScript中没有类。这与问题有什么关系？这与问题有什么关系？Person.prototype[params.method]。调用（self）
=self[params.method]（）
当实例超出范围时，事件侦听器仍在那里。Person.prototype[params.method]。调用（self）=self[params.method]（）
当您的实例超出范围时，事件侦听器仍然存在。如果您担心垃圾收集器，我认为您必须简单地将destroy方法添加到类原型中，并将侦听器与该对象分离。你怎么看？如果你担心垃圾收集器，我认为你必须简单地将destroy方法添加到类原型中，并将侦听器与该对象分离。你觉得怎么样？