Javascript-inheritance (prototype chaining)

The key is to set the prototype attribute of classb to the instance of classa.

 Function  Classb (color ){  This . Color = Color;  This . Saycolor = Function  () {Console. Log (  This  . Color );}}  Function  Classa (name ){  This . Name = Name; This . Sayname = Function  () {Console. Log (  This  . Name )}}
// This sentence allows a to inherit all the attributes and methods of B. classa. Prototype = New  Classb ();  VaR OA = New  Classa (); Oa. Color = "Red" ; Oa. saycolor (); 

 

The relationship is as follows:

Instance a can inherit all the attributes and methods in the classa. Prototype object.

Now classa. Prototype points to the classb instance

Therefore, instance a can have the attributes of all methods of the classb instance.

Classb instances can have all the attributes and methods of classb. prototype,

Therefore, instance a can also have all the attributes and methods of classb. prototype.

 

It is connected like a chain, so it is called a prototype chain.

Originally:

 

After classa. Prototype = new classb ();