Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
403 views
in Technique[技术] by (71.8m points)

javascript - Prototype chain: call "super" method over multiple levels

I have got the following prototype chain

  • SuperSuperClass
    • SuperClass
      • Class

each with a method named do.

What is the common approach for calling the respective super class method?
For the moment I use <ClassName>.prototype.__proto__.<methodName>.call(this) but that looks odd.

Using the following code the console prints (as expected):

  • Class.prototype.do
  • SuperClass.prototype.do
  • SuperSuperClass.prototype.do
SuperSuperClass = function SuperSuperClass() {}
SuperSuperClass.prototype.do = function() {
    console.log('SuperSuperClass.prototype.do');
};

function SuperClass() {
    SuperSuperClass.call(this);
}
SuperClass.prototype = Object.create(SuperSuperClass.prototype);
SuperClass.prototype.constructor = SuperClass;
SuperClass.prototype.do = function() {
    console.log('SuperClass.prototype.do');
    SuperClass.prototype.__proto__.do.call(this);
};

function Class() {
    SuperClass.call(this);
}
Class.prototype = Object.create(SuperClass.prototype);
Class.prototype.constructor = Class;
Class.prototype.do = function() {
    console.log('Class.prototype.do');
    Class.prototype.__proto__.do.call(this);
};

var objClass = new Class();
objClass.do();

JSFiddle

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

What is the common approach for calling the respective super class method?

Use <SuperClassName>.prototype.<methodName>.call(this). It's not only shorter, but also has the benefit of working in environments that don't support the non-standard __proto__ property.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...