javascript - 未捕获的 ReferenceError：未定义键
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javascript - Uncaught ReferenceError: keys is not defined
提问by user1767962
I am getting an error when I run the following command in an included script. But if I run the command from the google chrome console, it works properly.
在包含的脚本中运行以下命令时出现错误。但是如果我从 google chrome 控制台运行命令，它就可以正常工作。
var a = {};
console.log(keys(a));
Error:
错误：
Uncaught ReferenceError: keys is not defined
What's going on here? How can I use the keysfunction in an included script?
这里发生了什么？如何keys在包含的脚本中使用该函数？
回答by Alex Wayne
console.log(keys(a))
keys()is not function provided by the browser for use in your code. You probably want Object.keys()
keys()不是浏览器提供的用于您的代码的功能。你可能想要Object.keys()
a = {};
console.log(Object.keys(a));
Sometimes the console has extra functions exposed to it for ease of use debugging that aren't available in your actual code. keys()sounds like one, and copy('some text')is another.
有时，控制台会向它公开一些额外的功能，以便于使用调试，这些功能在您的实际代码中是不可用的。keys()听起来像一个，又copy('some text')是另一个。
I'm failing to find a link which lists them, sadly. But I'm quite sure there are more than those 2 functions.
遗憾的是，我找不到列出它们的链接。但我很确定不止这两个功能。
回答by 0x499602D2
Whenever you get an error like this, try to search for a definition of the function/variable that's been reported as undefined. If it isdefined, try looking for a reason this might not be working. Did you know that the keysfunction is apart of the Objectconstructor? You can't call it as if it's a free-standing function. Though if you get into the habit of doing this, try making your own function to allow this:
每当遇到这样的错误时，请尝试搜索报告为未定义的函数/变量的定义。如果已定义，请尝试寻找可能不起作用的原因。你知道这个keys函数是Object构造函数的一部分吗？你不能把它当作一个独立的函数来调用。但是，如果您养成了这样做的习惯，请尝试制作自己的函数以允许这样做：
function key( object ) {
return Object.keys( object );
}
Your code should pass given a definition like this.
您的代码应该通过这样的定义。
