Javascript 具有自引用的对象和数组

我对理解JavaScript行为非常感兴趣

对象：

object = {object : window.object};
object = {object : window.object};

console.log(object === object); // true
console.log(object.object === object); // false
console.log(object.object === object.object); // true
console.log(object.object.object === object.object); // false

数组：

array = [window.array];
array = [window.array];

console.log(array === array); // true
console.log(array[0] === array); // false
console.log(array[0] === array[0]) // true
console.log(array[0][0] === array[0]) // false

为什么

---

返回false？？？

有两个赋值给

window.object

。第一个创建一个新对象并将其分配给

window.object

。其中有一个名为“object”的属性，其值为

未定义

，因为在计算对象文本时

窗口。object

为

未定义

第二个赋值实例化一个新对象。该对象还有一个名为“object”的属性，其值是在第一次赋值中创建的对象

因此，

window.object

与

window.object.object

不是同一个对象

关键是在这样的作业中：

object = { object: window.object };

---

对象文字中“object”属性的值在赋值之前进行计算。在第一次赋值之后，您有以下内容：

object = { object: undefined }

第二个赋值创建一个新的对象，其

object

属性包含

window.object

的上一个值，并将其赋值给

object

。现在你有了：

object = { object: { object: undefined } }

所以此时，

object.object

是

{object:undefined}

，这与

object

不同

类似的事情也发生在数组示例中

如果要创建自引用对象，需要执行以下操作：

object = {};
object.object = object;

这不会在第二次指定中创建新对象，而是修改原始对象。然后你可以做：

console.log(object.object.object.object === object); // true

对于阵列，它将是：

array = [];
array[0] = array;
console.log(array[0][0][0][0][0] === array); // true

---

让我们逐行解释

    object = {object : window.object};
    //here object.object is undefined and object new object so object !== object.object
    //lets obj1 = {object: undefined}

    object = {object : window.object};
    //here object is new instance of Object while object.object is equal to older object
   //basically object != object.object 
    // obj2 = {object: obj1}
    console.log(object === object); // true because same object obj2 == obj2
    console.log(object.object === object); // false because two different object  as obj1 != obj2
    console.log(object.object === object.object); // true because same object obj1 == obj1
    console.log(object.object.object === object.object); // false because undefined != obj1 

---

为什么定义变量两次，然后覆盖它？编辑：ok；）如果你知道答案，为什么要发布这个问题？那么有两个对象？是的，有两个对象。为什么没有呢？每个不同的对象文字表达式都会创建一个新对象。

    object = {object : window.object};
    //here object.object is undefined and object new object so object !== object.object
    //lets obj1 = {object: undefined}

    object = {object : window.object};
    //here object is new instance of Object while object.object is equal to older object
   //basically object != object.object 
    // obj2 = {object: obj1}
    console.log(object === object); // true because same object obj2 == obj2
    console.log(object.object === object); // false because two different object  as obj1 != obj2
    console.log(object.object === object.object); // true because same object obj1 == obj1
    console.log(object.object.object === object.object); // false because undefined != obj1