使用变量作为函数和对象实例 [英] Use a variable both as function and object instance

问题描述

我想知道 JQuery 如何使用 "$" 作为返回新实例和实例本身的函数.我想情况并非完全如此，但我的意思是，我们可以使用 $(element).method 并且例如 $.ajax 没有括号(.ajax 仍然是一个方法).

I was wondering how does JQuery use "$" both as a function to return a new instance and an instance itself. I guess that it's not exactly the case but I mean, we can use $(element).method and for exemple $.ajax without brackets (.ajax will still be a method).

我想我说错了.我知道对象在 JavaScript 中是如何工作的，我的问题与此无关.JQuery 允许我们使用 $ 而没有关键字 new.它有一个自动返回一个新实例的函数.所以我的问题是关于它如何使用 $ 作为一个函数来实例化一个新对象和一个对象本身.假设我们有

EDIT : I think that I misspoke. I know how objects work in JavaScript and my question was not about that. JQuery allows us to use $ without the key word new. It has a function that returns a new instance automatically. So my question was about how it can use $ both as a function to instanciate a new object and an object itself. Let's say we have

(function() {

var jQ = function (arg){

    this.own = arg;

};

jQ.prototype = {

    foo : function (){

        alert("Foo");

    },

    bar : function (){

        alert("Bar");

    }

};

window.jQ = window.$ = jQ;

return jQ;

}());在这个例子中，如果我想使用我的对象，我必须通过关键字new.那么JQuery是如何避免我们这一步的呢?

}()); In this exemple, i have to go througth the key word new if I want to use my object. So how does JQuery do to avoid us this step ?

推荐答案

Function 是 javascript 中的一个对象:https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function 您可以查看此代码:

Function is an object in javascript: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function You can check this code:

var f = function () { alert(1); };
f.func1 = function () { alert(2); };
f.func2 = function () { alert(3); };

你可以调用f()、f.func1()等等...

and you can call f(), f.func1() and so on...

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