In JS, we can see it through an OOP idea. Where function is the key word throughout the JS structure, using the function keyword to create a series of internal (that is, JS itself comes with the class), such as: object,array,string, etc., since the JS structure is clearly clear.
You can verify that the constructor, such as Object,array, are Function () {}.
Then in passing var a = new Object (), you can find that the constructor of a is object () {}; This is probably the JS schema.
We can also use the function to produce similar objects and arrays, such as the class, to achieve our own needs, and then with the JS comes with the class can do a variety of functions.
But there is one other thing: The object class is the ancestor class of the majority (whether it is all yet to be studied), and the primitive ancestor class of array is also the object class.
JS's structure type understanding