javascript 基础对象用不同的方法创建另外两个对象

Question

多年来我一直在研究 javascript，但现在我正努力认真起来。学习，并进入对象。

我想创建一个基础对象，并用它来创建另外 2 个略有不同的对象。

我认为这会起作用:

function movingObject(x, y, z){
   this.x = x;
   this.y = y;
   this.z = z;
}

var positiveMover = new movingObject(x, y, z);
positiveMover.prototype.move = function(a, b){
    yadda yadda
}

var negativeMover = new movingObject(x, y, z);
negativeMover.prototype.move = function(b, a){
    adday adday
}

var pic = postiveMover(1, 2, 3);
pic.move(20, 10);

我在移动时遇到未定义的错误......很确定我的想法是错误的。任何建议将不胜感激 - 信息链接或谷歌的正确关键字

Answer 1

我认为它更像是您要构建的两个类:

function movingObject(x, y, z){
   this.x = x;       this.y = y;       this.z = z;
}

// positive mover : child class of movingObject    
function positiveMover (x, y, z) {  
    // use parent class's constructor.
    movingObject.apply(this,arguments); 
};

// inherit parent's class.
positiveMover.prototype = Object.create(movingObject.prototype); 

positiveMover.prototype.move = function(a, b){   yadda yadda    }

但是，如果您寻求按实例选择方法，您可以这样做:

function movingObject(x, y, z, movingMethod){
   this.x = x;       this.y = y;       this.z = z;
   this.move = movingMethod;
}

或者只是设置移动对象的移动属性，从而覆盖默认原型(prototype):

function movingObject(x, y, z){
   this.x = x;       this.y = y;       this.z = z;
}
movingObject.prototype.move= function(a,b) { /*some default code*/}

var oneMover = new movingObject(0,0,0);
oneMover.move = function(a,b) { /* some specific code */ };