javascript 无法读取未定义的属性“匹配”
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Cannot read property 'match' of undefined
提问by rob.m
I'm running the following:
我正在运行以下内容：
var token = document.location.href.split('?s=')[1].match(/[a-z0-9]+/);
var longString = "?s=" + token + "?_sft_category=";
var tokenB = document.location.href.split(longString)[1].match(/[a-z0-9]+/);
var attribuB = "." + tokenB;
jQuery('a[data-filter-value="' + attribuB + '"]').parent().parent().parent().find(".dropdown-toggle").html(tokenB).append(' <span class="caret"></span>');
How come I get?
我怎么得到？
Uncaught TypeError: Cannot read property 'match' of undefined
If I remove .match(/[a-z0-9]+/)i don't get any error, but I do need match..
如果我删除.match(/[a-z0-9]+/)我不会收到任何错误，但我确实需要match..
The URL looks like:
该网址如下所示：
http://www.example.com/xchanges/results/?s=sky&_sft_category=ogilvy
采纳答案by Cyclonecode
You are using ?twice in longString, which in turn will make split()return an array with only one value. You need to change it to:
您?在 in中使用了两次longString，这反过来将split()返回一个只有一个值的数组。您需要将其更改为：
var longString = "?s=" + token + "&_sft_category=";
The ?character should only be used once, at the start of the querystring.
该?字符只能在查询字符串的开头使用一次。
回答by Ionic? Biz?u
Probably using a library would be better here. I developed a tiny JavaScript library that work with the urls: url.js.
可能在这里使用图书馆会更好。我开发了一个使用 urls 的小型 JavaScript 库：url.js.
<script src="path/to/url.js"></script>
<script src="your-js.js"></script>
Then you can do:
然后你可以这样做：
var token = Url.queryString("s");
var tokenB = Url.queryString("_sft_category");
And that's it.
就是这样。
Note that instead of calling parent()multiple times, you can use the closest()method:
请注意parent()，您可以使用该closest()方法，而不是多次调用：
$('a[data-filter-value="' + attribuB + '"]')
.closest("<your_container>")
.find(".dropdown-toggle")
.html(tokenB)
.append(' <span class="caret"></span>')
;
回答by Reinder Wit
Your location.href probably doesn't contain your longString. If you split the hrefusing a string that's not present in href, you're left with an array with only 1 string, so you cannot get the [1] element.
It all depends on what your tokenvariable is....
您的 location.href 可能不包含您的longString. 如果您href使用 中不存在的字符串拆分href，则会留下一个只有 1 个字符串的数组，因此您无法获得 [1] 元素。这一切都取决于你的token变量是什么......
You've used a '?' character twice, which is incorrect. I'd use
你用过'?' 字符两次，这是不正确的。我会用
var tokenB = document.location.href.split('_sft_category=')[1].match(/[a-z0-9]+/);
to get the desired value, as _sft_category=will probably only occur once in location.href and you should then be able to split the href into an array of 2.
Saves you 2 lines of code ;) ...
以获得所需的值，因为_sft_category=可能只会在 location.href 中出现一次，然后您应该能够将 href 拆分为 2 的数组。为您节省 2 行代码；) ...
