如何按照编写的顺序迭代javascript对象属性 [英] How to iterate javascript object properties in the order they were written

问题描述

我发现我的代码中存在一个错误，希望通过最少的重构努力来解决。 Chrome和Opera浏览器中会出现此错误。
问题：

I identified a bug in my code which I hope to solve with minimal refactoring effort. This bug occurs in Chrome and Opera browsers. Problem:

var obj = {23:"AA",12:"BB"};
//iterating through obj's properties
for(i in obj)
  document.write("Key: "+i +" "+"Value: "+obj[i]);

FF输出，IE
键：23价值：AA
关键： 12价值：BB

Output in FF,IE Key: 23 Value: AA Key: 12 Value: BB

Opera和Chrome中的输出（错误）

键：12值BB
关键：23价值AA

Output in Opera and Chrome (Wrong)
Key: 12 Value BB
Key: 23 Value AA

我试图制作一个这样的逆序对象

I attempted to make an inverse ordered object like this

var obj1={"AA":23,"BB":12};
for(i in obj1)
  document.write("Key: "+obj[i] +" "+"Value: "+i);

然而输出是相同的。是否有办法通过较小的更改获得所有浏览器相同的行为？

However the output is the same. Is there a way to get for all browser the same behaviour with small changes?

推荐答案

否。 JavaScript对象属性没有固有的顺序。总算很幸运，在循环运行时，的顺序是什么。

No. JavaScript Object properties have no inherent order. It is total luck what order a for...in loop operates.

如果你想订购，你会必须改为使用数组：

If you want order you'll have to use an array instead:

var map= [[23, 'AA'], [12, 'BB']];
for (var i= 0; i<map.length; i++)
    document.write('Key '+map[i][0]+', value: '+map[i][1]);

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