jQuery的返回值是Array，但构造函数是Object。 怎么样？

Question

for example,

$(document) // [ #document ] : document object in array
typeof $(document) // "object"
$(document).constructor // function Object() { [native code] } or function (a,b) { return some function; }

If value is array, it have to be Array constructor.

It's not an array like object. because array like object just has array property, not like [].

How can it be?

add: If you can, show simple example code, please. like

a = ... 
console.log(a) // [ ... ]
console.log(a.constructor) // function Object or something

Answer 1

Take a look at the jQuery source . $(document) creates a cloned jQuery object of the document element and then makes and returns an array-like object .

the jQuery factory function $() returns a jQuery object that has many of the properties of an array (a length, the [] array access operator, etc.), but is not exactly the same as an array and lacks some of an array's built-in methods (such as .pop() and .reverse()).

Answer 2

An array, as in [] , is also an object in JavaScript. In JS mostly everything is an object, such as functions, arrays, literal objects, regular expressions... To really know what you're dealing with is an array you can do this:

Object.prototype.toString.apply(myarray) === '[object Array]'