我如何将console.log功能与其所有属性一起使用？

Question

I'm using the Google Chrome console. Frustratingly, the following code

var f = function () {};
f.a = 1;
console.log(f);

will only log

function () {}

Why does it not print the properties of f , such as fa and f.prototype ? How can I print them?

Answer 1

试试console.dir 。

console.dir(f);

Answer 2

console.dir lists all the defined properties of an object. I think this is probably what you're looking for.

How this appears in FF (Firebug)

How this appears in Chromium's console

I'm not sure if there's any Chrome documentation on this functionality, but there is Firebug documentation on the console object.

Answer 3

Because a function is not an object.

If you do:

var f = function () {};
var my_instance = new f();  // aha!
my_instance.a = 1;
console.log(my_instance);

You should get what you expect.

A function can be a class, but never an object. Use new .