Js prototype chain principles

At the beginning, the inventor of ECMAscript designed the linked list to simplify the language and maintain the inherited attributes ..
The linked list is not learned in the data structure. A position in the linked list is equivalent to a pointer and points to the next struct.

The same is true for _ proto _. When you define a prototype, _ proto _ of the Instance points to a struct, the directed struct is called the prototype of the instance.

The text is a bit difficult to say.
Copy codeThe Code is as follows:
Var foo = {
X: 10,
Y: 20
};

When I do not specify _ proto _, foo reserves such an attribute,

If there is a clear point, the linked list will be linked.

Obviously, B and c share the attributes and methods of a and have their own private attributes.

_ Proto _ is also pointed to by default. It points to the highest level of object. prototype, while the _ proto _ of object. prototype is null.
Copy codeThe Code is as follows:
Var a = {
X: 10,
Calculate: function (z ){
Return this. x + this. y + z
}
};
Var B = {
Y: 20,
_ Proto __:
};

Var c = {
Y: 30,
_ Proto __:
};

// Call the inherited method
B. calculate (30); // 60

Understand the essence of the property link pointer _ proto .. Then we can understand constructor.

When a prototype is defined, a prototype object is constructed. The prototype object is stored in the prototype method used to construct the prototype function.
Copy codeThe Code is as follows:
Function Foo (y ){
This. y = y;
}

Foo. prototype. x = 10;

Foo. prototype. calculate = function (z ){
Return this. x + this. y + z;
};

Var B = new Foo (20 );

Alert (B. calculate (30 ));

[Reference]

Http://dmitrysoshnikov.com/ecmascript/javascript-the-core/