如何使用具有多個子原型對象的原型嵌套對象和共享變量？

Question

我是 JavaScript 新手，我試圖了解繼承是如何工作的，我之前使用過 C++，並且很容易處理從主類到它們的后代的變量，我嘗試過原型方法，但並不那么容易。 這是我的代碼......正確的方法是什么？？？

 function main() { this.name = "main object, name"; } main.prototype.LevelA1 = function() { return "LevelA1 method " + this.name; //this level read this.name right } main.prototype.LevelA = function() { this.a = "laaaa" return "LevelA " + this.name; //variable this.name is visible } main.prototype.LevelA.LevelB = function() { return this.name + " Level B " + this.a //this.name undefined } main.prototype.LevelA.LevelB.LevelC = function() { return "level C" + this.name; //this.name not visible and not produce error } main.prototype.LevelA.LevelB.LevelC.LevelD = function() { this.bb = "variable of levelD" return "Level D " + this.bb + this.name; //this.name not visible and ot produce error } m = new main(); console.log(m.LevelA()); console.log(m.LevelA.LevelB()); console.log(m.LevelA.LevelB.LevelC()); console.log(m.LevelA.LevelB.LevelC.LevelD()); var cc = new m.LevelA.LevelB.LevelC.LevelD(); console.log(cc.bb);

Answer 1

您正在設置新函數而不是設置新原型，因此每個新函數的詞法上下文與Main.prototype 。

我建議您使用類來處理您的邏輯。

這種方法將“Level”函數包裝在從Main類擴展的類中。

 class Main { constructor() { this.name = "main object, name"; } } class MainLevel extends Main { LevelA1() { return "LevelA1 method " + this.name; //this level read this.name right } LevelA() { this.a = "laaaa" return "LevelA " + this.name; //variable this.name is visible } LevelB() { return this.name + " Level B " + this.a //this.name undefined } LevelC() { return "level C" + this.name; //this.name not visible and not produce error } LevelD() { this.bb = "variable of levelD" return "Level D " + this.bb + this.name; //this.name not visible and ot produce error } } let m = new MainLevel(); console.log(m.LevelA()); console.log(m.LevelB()); console.log(m.LevelC()); console.log(m.LevelD());