1: What is a constructor?
To understand what a constructor is, you need to understand the difference between a normal function and a constructor.
// A normal function
var Parent = function() {};// Parent is a constructor, and p1 is its instance
var p1 = new Parent();
Copy the code2: What is unique
protoThe constructor attribute is unique to the object
The Prototype attribute is unique to the function
Functions are also objects, so functions also have attributes __proto__ and constructor
3: Prototype attribute
We can use prototype to add attributes to a function, and all instantiated objects of this function can inherit the attributes we added through it.
Usage:
Function name. Prototype instead of object name
4: Pointing relationship between constructor and prototype object
Constructor = p1; constructor = p1constructorMethod, fromp1I got it from the prototype.Copy the code