分配操作是否总是从右向左复制数据？

Question

看一看这段JavaScript代码：

var myString = new String(); 
myString.myObject = "myObject..."; 

//works fine as it shows "myObject..." 
console.log("myString.myObject  :" + myString.myObject); 
//OK myObject is also a string so it should give length and it works fine 
console.log("myString.myObject.length :" + myString.myObject.length); 
//it should not give anything or undefined since nothing is given to myString 
console.log("myString     :" + myString); 
//myString is not yet defined so it should give undefined or 0.. 
console.log("myString.length   :" + myString.length); 

//lets make a simple assignment 
myString = myString.myObject; 
//it should just copy value of myObject to myString so there are two copies of string "myObject.." 

//lets log all the data all the data as i did above 

console.log("myString.myObject  :" + myString.myObject); 

//and this part is giving error 
//console.log("myString.myObject.length :" + myString.myObject.length); 

console.log("myString     :" + myString); 
console.log("myString.length   :" + myString.length); 

在上半年（赋值之前），它正在为我所预期，但转让之后它给出了一个错误。

看来myString.myObject在分配后被删除。是吗？。

当我尝试访问myString.myObject时，控制台出现红色错误。分配删除myString.myObject，还是发生在这里？

Answer 1

当你做到这一点

myString = myString.myObject; 

你与它的myObject属性值替换整个myString值。由于它本身没有myObject属性，因此您在分配后没有。

完成此作业后，myString的值为"myObject..."。