在console.log错误？ [英] Bug in console.log?

问题描述

可能重复：

Possible Duplicate:
Is Chrome's JavaScript console lazy about evaluating arrays?

我试试下面的代码：

var myList = new Object();
var item   = new Object();
item.text  = "item-1";
myList[3]  = item;

console.log(myList);
console.log(myList[3].text);

// Assign another object to the same entry
var item2   = new Object();
item2.text  = "item-2";
myList[3]  = item2;

console.log(myList);
console.log(myList[3].text);

结果很奇怪：

* Object
  * 3: Object
      text: "item-2"

item-1

* Object
  * 3: Object
      text: "item-2"

item-2

但是 - 如果我在一段时间后执行第二部分（使用setTimeout），并展开第一个对象，我得到它对，即：

BUT - if i execute the second part after some time (using setTimeout), and unfold the first object, I get it right, i.e.:

* Object
  * 3: Object
      text: "item-1"

item-1

* Object
  * 3: Object
      text: "item-2"

item-2

我觉得分享它很重要，因为我认为可以浪费很多时间来理解他的代码有什么问题。
如果有人提到一个开放的错误或东西 - 请回复这张票。
谢谢！

I find it important to share it, since I think one can waste a lot of time trying to understand what's wrong in his code. And if somebody has some reference to an open bug or something - please reply this ticket. Thanks!

推荐答案

我的观点是，这是一个可怕的刺激的'功能'，我真的希望我能关闭，它使调试噩梦，不知道在什么时间点，可能已更新了一个对象，同时试图建立确切的对象状态在代码中的给定点。该功能对于观察点等可能有用，但不是在称为LOG的东西（该线索在名称中）。

My view is that this is a horrendously irritating 'feature' that I really wish I could turn off, it makes debugging a nightmare, not knowing at which point in time something may have updated an object, whilst trying to establish exact object state at a give point in the code. The feature could be useful for 'watch points' etc, but not in something called a 'LOG' (the clue is in the name).

考虑这个代码片段：

var person = {'name':'Tom'};
console.log( person);  //output the entire object variable
person.name = 'Thomas';
//the output is an object, whose 'name' value is 'Thomas', even though the log statement was placed before the value was changed to 'Thomas'.

然后：

var person = {'name':'Tom'};
console.log( person.name);    //changed to output a string variable
person.name = 'Thomas';
//the output here, however, has not dynamically updated and correctly outputs 'Tom'

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