使用原型与JavaScript的公共方法

Question

I am looking to create public and private methods for javascript functions with return statements.

I like the idea of using return to pass back the publicly accessible methods because it easy to see all of your public properties and methods in one place.

var Base = function(){
  var method1 = function(){
    console.log("method1");
  }
  var method2 = function(){
    console.log("method2");
  }
  //private
  var method3 = function(){
    console.log("method3");
  }
  // public methods
  return {
    method1:method1,
    method2:method2
  }
}
var Child = function(){
  var method4 = function(){
    console.log("method4");
  }
  var method5 = function(){
    console.log("method5");
  }
  //private
  var method6 = function(){
    console.log("method6");
  }
  // public methods
  return {
    method4:method4,
    method5:method5

  }
}
Child.prototype = new Base();

var base = new Base();
base.method1();
base.method2();

var child = new Child();
try {
  child.method1();
} catch(e){
  console.log(e.message);
}
try {
  child.method2();
} catch(e){
  console.log(e.message);
}
child.method4();
child.method5();

I know if I do it like this I will get the public/private methods, but I was wondering if anyone knew how to do it with the return statement.

var Base = function(){
  // public methods
  this.method1 = function(){
    console.log("method1");
  };
  this.method2 = function(){
    console.log("method2");
  };
  // private methods
  var method3 = function(){
    console.log("method2");
  };
};
var Child = function(){
  // public methods
  this.method4 = function(){
    console.log("method4");
  };
  this.method5 = function(){
    console.log("method5");
  };
  // private methods
  var method6 = function(){
    console.log("method6");
  };
};
Child.prototype = new Base();

var base = new Base();
base.method1();
base.method2();

var child = new Child();
child.method1();
child.method2();
child.method4();
child.method5();

Answer 1

No. You must not use return if you want to use prototypical inheritance, you should use this as it is the instance object that inherits from your prototype.

Of course, nothing prevents you from congregating your public interface in the end of the constructor:

function Base() {
  function method1() {
    console.log("method1");
  }
  function method2() {
    console.log("method2");
  }
  //private
  function method3() {
    console.log("method3");
  }
  // public methods
  this.method1 = method1;
  this.method2 = method2;
}

Notice that you should not use new Base for the inheritance of Child.prototype .