Javascript继承和基类原型的问题

Question

I'm facing issues with configuring object while inheriting So I've

baseclass.prototype.activity =function(){ console.log("Im"+activity); }

and multiple other objects inheriting the base class(say A and B).

I want to configure run based on type of A and B So if it is A then calling run should make activity as Running and similarly with B it can be swimming I'm using following factory method for creating A and B depending on their type

activityFactoryObject.prototype.makeObj = Object.create(baseclass);
activityFactoryObject.prototype.createObject = function (config) {

    switch (config) {
    case "running":

        this.makeObj = A;
        break;
    case "swimming":

        this.makeObj = B;

        break;
    }
    this.makeObj.prototype = baseclass.prototype;  
    return new this.makeObj(config); 

};

Answer 1

Im not sure exactly what your goal is but if they are both inheriting from baseClass and the only difference is what activity displays then something like this would be sufficient:

baseClass.protoype.activity = function ( activity ) { console.log( "I'm " + activity ); };

var a = new BaseClass(),
    b = new BaseClass();

a.activity( 'Running' ); // -> "I'm Running"
b.activity( 'Swimming' ); // -> "I'm Swimming"

Answer 2

Not sure if this is what you're after:

var Activity = function(argsObj){
  this.activityType = argsObj.activityType || "Default value";
};
Activity.prototype.doIt = function(){
  console.log("I am " + this.activityType);
};

var Run = function(argsObj){
  //re use Activity initializer
  Activity.apply(this,arguments);
};
Run.prototype=Object.create(Activity.prototype);
Run.prototype.constructor = Run;

var Swim = function(argsObj){
  //re use Activity initializer
  Activity.apply(this,arguments);
};
Swim.prototype=Object.create(Activity.prototype);
Swim.prototype.constructor = Swim;

function activityFactory(argsObj){
  return new window[argsObj.type](argsObj);
}

var r = activityFactory({type:"Run",activityType:"running"});
var s = activityFactory({type:"Swim",activityType:"swimming"});
r.doIt();//I am running
s.doIt();//I am swimming
console.log(r instanceof Run);//true
console.log(s instanceof Swim);//true
console.log(s instanceof Activity);//true
var wrong = activityFactory({type:"Run"});
wrong.doIt();//I am Default value

More on constructor functions and prototype: https://stackoverflow.com/a/16063711/1641941