我有个问题。当我从一个对象实例时，它不返回构造函数的值。 .................................................. .................................................. .................................................. .......... ........................................ .................................................. .................................................. ....................
//Main Branch
var Creatures = function () {
function Creatures(name,alive) {
this.name = name;
this.alive = alive;
}
function Creatuers(name,alive,sleep) {
this.name = name;
this.alive = alive;
this.sleep = sleep;
}
};
var Beast = function () {
function breathe() {
return true;
}
this.__proto__ = new Creatures;
};
var Mammals = function () {
this.numberOfBeads = "i am numberOfBeads from Mammals";
this.__proto__ = new Beast;
};
//Mammals Branch
var Humans = function () {
function thinking(){
return true;
}
this.love = "i am love from humans";
this.__proto__ = new Mammals;
};
var Animals = function () {
this.instinct = "i am Animals from Animals";
this.__proto__ = new Mammals;
};
var Plants = function () {
this.color = "i am color from Plants";
function grown() {
return true;
}
this.__proto__ = new Creatures;
};
var Trees = function () {
this.height = "i am height from Trees";
this.__proto__ = new Plants;
};
var Flowers = function () {
this.smell = "i am smell from Flowers";
this.__proto__ = new Plants;
};
var Grasses = function () {
this.color = "i am color from Grasses";
this.__proto__ = new Plants;
};
var obj2 = new Creatures("ali",true);
alert(obj2.name);<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Index</title>
</head>
<body>
<script src="sampleObject1.js"></script>
<script src="sampleObject2.js"></script>
</body>
</html>如果你指的是var obj2 = new Creatures("ali",true);它会返回一个实例！它不返回具有属性name和alive的新Creatures实例，因为它们不是构造函数的参数，也不是构造函数中设置的属性（顶级一）：
var Creatures = function () {
...
};
你似乎要做的是创建重载的构造函数？！ javascript不支持函数重载！
我可以确认@Denys Seguret说，某些事情似乎相当模糊......
无论如何，你得到未定义，因为函数构造函数返回一个对象，该对象具有你在该函数构造函数中附加的属性。
在您的情况下，您的功能是：
var Creatures = function () {
function Creatures(name,alive) {
this.name = name;
this.alive = alive;
}
function Creatures(name,alive,sleep) {
this.name = name;
this.alive = alive;
this.sleep = sleep;
}
};
这是一个函数表达式，在其范围内有两个具有相同名称的函数（第二个函数将覆盖第一个，尽管第一个函数没用）。
如您所见，您没有为将从其隐式返回的对象设置任何类型的属性。
我让你的例子只是用第二个函数声明替换它：
function Creatures(name,alive,sleep) {
this.name = name;
this.alive = alive;
this.sleep = sleep;
}
var obj2 = new Creatures("ali", true);
alert(obj2.name);这会发出一个警告“阿里”。
你在函数中没有任何return语句
var Creatures = function () {
function Creatures(name,alive) {
this.name = name;
this.alive = alive;
}
function Creatuers(name,alive,sleep) {
this.name = name;
this.alive = alive;
this.sleep = sleep;
}
};
您可能要做的是委托对象的实例化，根据参数（可能还有一些业务逻辑）选择合适的构造函数。注意javascript中没有方法重载，所以你需要为内部函数使用不同的命名。
var Creatures = function (...params) {
function Creatures1(name,alive) {
this.name = name;
this.alive = alive;
}
function Creatures2(name,alive,sleep) {
this.name = name;
this.alive = alive;
this.sleep = sleep;
}
return params.length === 2 ? new Creatures1(...params) : new Creatures2(...params);
};
var obj2 = Creatures("ali",true);
alert(obj2.name);