javascript - 检查object是否是jQuery对象(Check if object is a jQuery object)

Question

Is there a fast way of checking if an object is a jQuery object or a native JavaScript object?(有没有快速检查对象是jQuery对象还是本机JavaScript对象的方法？)

example:(例：) var o = {}; var e = $('#element'); function doStuff(o) { if (o.selector) { console.log('object is jQuery'); } } doStuff(o); doStuff(e); obviously, the code above works but it's not safe.(显然，上面的代码有效，但不安全。) You could potentially add a selector key to the o object and get the same result.(您可以将选择键添加到o对象并获得相同的结果。) Is there a better way of making sure that the object actually is a jQuery object?(有没有更好的方法来确保对象实际上是一个jQuery对象？) Something in line with (typeof obj == 'jquery')(符合的东西(typeof obj == 'jquery'))   ask by David Hellsing translate from so

Answer 1

You can use the instanceof operator:(您可以使用instanceof运算符：)

obj instanceof jQuery Explanation : the jQuery function (aka $ ) is implemented as a constructor function .(说明 ： jQuery函数（又名$ ）是作为构造函数实现的 。) Constructor functions are to be called with the new prefix.(使用new前缀调用构造函数。) When you call $(foo) , internally jQuery translates this to new jQuery(foo) ¹ .(当你调用$(foo) ，内部jQuery会将其转换为new jQuery(foo) ¹ 。) JavaScript proceeds to initialize this inside the constructor function to point to a new instance of jQuery , setting it's properties to those found on jQuery.prototype (aka jQuery.fn ).(JavaScript继续在构造函数内初始化this以指向jQuery的新实例，将其属性设置为jQuery.prototype （aka jQuery.fn ）上的属性。) Thus, you get a new object where instanceof jQuery is true .(因此，您将获得一个new对象，其中instanceof jQuery为true 。) ¹ _{It's actually new jQuery.prototype.init(foo) : the constructor logic has been offloaded to another constructor function called init , but the concept is the same.}(¹ _{它实际上是new jQuery.prototype.init(foo) ：构造函数逻辑已被卸载到另一个名为init构造函数，但概念是相同的。})