javascript IE 问题 - 不支持 Object.keys(value).length
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IE issue - Object.keys(value).length not supported
提问by veryConfused
I've been trying to debug some js in Internet Explorer, and I can't figure this one out. Here's the line that is causing the error:
我一直在尝试在 Internet Explorer 中调试一些 js，但我无法弄清楚这一点。这是导致错误的行：
var numberOfColumns = Object.keys(value).length;
And the error is...
而错误是...
Message: Object doesn't support this property or method
Line: 640
Char: 5
Code: 0
URI: xxx
At first I thought it had something to do with the Object.keys(value).length;property, but strangely (for me anyways), the error is at char 5, which is the beginning of the variable name.
起初我认为它与Object.keys(value).length;属性有关，但奇怪的是（无论如何对我来说），错误出现在 char 5，这是变量名的开头。
Anyways, I have no idea what's going on or how to fix it. Also, if I replace:
无论如何，我不知道发生了什么或如何解决它。另外，如果我替换：
var numberOfColumns = Object.keys(value).length;
With ...
和 ...
var numberOfColumns = 9; // troubleshooting
The error persists. Please help.
错误仍然存在。请帮忙。
Update
更新
jsFiddle added
添加了 jsFiddle
回答by Asad Saeeduddin
The keysproperty is supported in IE >= 9. You are probably testing it in an earlier version. A simple workaround is:
该keys属性在 IE >= 9 中受支持。您可能正在早期版本中测试它。一个简单的解决方法是：
var length = 0;
for(var prop in data){
if(data.hasOwnProperty(prop))
length++;
}
Here is a demonstration: http://jsfiddle.net/vKr8a/
这是一个演示：http: //jsfiddle.net/vKr8a/
See this compatibility table for more info:
有关详细信息，请参阅此兼容性表：
回答by digout
Alternatively, you could use a recommended polyfill for browsers that don't natively support Object.keys
或者，您可以为本机不支持的浏览器使用推荐的 polyfill Object.keys
Object.keys=Object.keys||function(o,k,r){r=[];for(k in o)r.hasOwnProperty.call(o,k)&&r.push(k);return r}
A break down of what this script does:
分解此脚本的作用：
Object.keys = Object.keys || function(o,k,r) {
// If the script doesn't detect native Object.keys
// support, it will put a function in its place (polyfill)
r=[];
// Initiate the return value, empty array
for(k in o) r.hasOwnProperty.call(o,k)
// loop through all items in the object and verify each
// key is a property of the object (`for in` will return non
// properties)
&& r.push(k);
// if it is a property, save to return array
return r
}
回答by nozzleman
Object.keyshas been introduced in ECMAScript 5th Edition. So if you IE-version is lower than 9, it will not be supported.
Object.keys已在 ECMAScript 第 5 版中引入。因此，如果您的 IE 版本低于 9，则将不支持。
