Chrome开发人员工具中奇怪的console.log行为 [英] Bizarre console.log behaviour in Chrome Developer Tools

问题描述

可能存在重复：

打开Chrome开发者工具并输入：

var a = []; console.log（a）; a。 push（1）; console.log（a）;

你会希望这会输出类似于

  [] 
 [1] 
  

但是，它输出

  [1] 
 [1] 
  
 
 $ b 
 
 $ b 
  var a的行为是一样的= []; console.log（a）; a [0] = 1; console.log（a）;  
 
 
 
任何人都可以解释这种行为？
 
 
 
在OS X上运行Chrome。在32位Windows 7上有相同的行为。 
 $ b  编辑：无论是否是sta，行为都是一样的帐单是否在同一行上。 
 
 
 
放置
我们在一行中简单地提供了它们以便于测试。  var a = []; 
 console.log（a）; 
.p.p（1）; 
 console.log（a）; 
  
在一个文件中运行它会产生相同的行为。
 
 
 
 编辑x 2  
请参阅： http：// jsfiddle。 net / 9N4A6 / ，如果你不想做一个文件测试。      
  var a = [];的console.log（a.toString（））; a.push（1）;的console.log（a.toString（））; 
  
这并不是说评估顺序很奇怪，我敢打赌，但是将对象转换为可打印的表单发生在所有语句全部执行后，即在Chrome准备好实际转储日志时。
 

  
Possible Duplicate:

  Is Chrome's JavaScript console lazy about evaluating arrays?  
Open up Chrome Developer Tools and type in:

var a = [];console.log(a);a.push(1);console.log(a);

You would expect this to output something like
[]
[1]
But instead it outputs
[1]
[1]
The behaviour is the same for

var a = [];console.log(a);a[0] = 1;console.log(a);

Can anyone explain this behaviour?

Running Chrome on OS X. Same behaviour on 32bit Windows 7.

EDIT: The behaviour is the same regardless of whether the statements are on the same line or not. I have simply provided them on a single line to make it easy to test.

Putting
var a = [];
console.log(a);
a.push(1);
console.log(a);
in a file then running it yields the same behaviour.

EDIT x 2
See: http://jsfiddle.net/9N4A6/ if you don't feel like making a file to test.
解决方案
Try this instead:
var a = []; console.log(a.toString()); a.push(1); console.log(a.toString());
It's not that the order of evaluation is strange, I bet, but that the conversion of the objects to printable form happens after the statements are all executed, at the point when Chrome is ready to actually dump out the log.

                        
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