Javascript Try / Catch
[英]Javascript Try/Catch
问题描述
I've got a function that runs a user generated Regex. 
我有一个运行用户生成的正则表达式的函数。 However, if the user enters a regex that won't run then it stops and falls over. 但是，如果用户输入了不会运行的正则表达式，则它会停止并翻倒。 I've tried wrapping the line in a Try/Catch block but alas nothing happens. 我已经尝试在Try / Catch块中包装该行但是没有任何反应。
If it helps, I'm running jQuery but the code below does not have it as I'm guessing that it's a little more fundamental than that. 如果它有帮助，我正在运行jQuery但是下面的代码没有它，因为我猜它比那更基础。
Edit: Yes, I know that I am not escaping the "[", that's intentional and the point of the question. 编辑：是的，我知道我没有逃避“[”，这是故意和问题的重点。 I'm accepting user input and I want to find a way to catch this sort of problem without the application falling flat on it's face. 我正在接受用户输入，我想找到一种方法来捕捉这种问题，而不会让应用程序掉到脸上。
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<title>Regex</title>
<script type="text/javascript" charset="utf-8">
var grep = new RegExp('gr[');
try
{
var results = grep.exec('bob went to town');
}
catch (e)
{
//Do nothing?
}
alert('If you can see this then the script kept going');
</script>
</head>
<body>
</body>
</html>
6 个解决方案
解决方案1
17 已采纳 2008-09-23 12:42:05
Try this the new RegExp is throwing the exception 试试这个新的RegExp抛出异常
Regex 正则表达式
<script type="text/javascript" charset="utf-8">
var grep;
try {
grep = new RegExp("gr[");
}
catch(e) {
alert(e);
}
try
{
var results = grep.exec('bob went to town');
}
catch (e)
{
//Do nothing?
}
alert('If you can see this then the script kept going');
</script>
解决方案2
8 2008-09-23 12:37:39
The problem is with this line: 问题出在这一行：
var grep = new RegExp('gr[');
'[' is a special character so it needs to be escaped. '['是一个特殊字符，因此需要进行转义。 Also this line is not wrapped in try...catch, so you still get the error. 此行也不包含在try ... catch中，因此您仍然会收到错误。
Edit : You could also add an 编辑 ：你也可以添加一个
alert(e.message);
in the catch clause to see the error message. 在catch子句中查看错误消息。 It's useful for all kind of errors in javascript. 它对javascript中的所有错误都很有用。
Edit 2 : OK, I needed to read more carefully the question, but the answer is still there. 编辑2 ：好的，我需要仔细阅读这个问题，但答案仍然存在。 In the example code the offending line is not wrapped in the try...catch block. 在示例代码中，违规行未包含在try ... catch块中。 I put it there and didn't get errors in Opera 9.5, FF3 and IE7. 我把它放在那里，并没有在Opera 9.5，FF3和IE7中出错。
解决方案3
4 2008-09-23 12:55:55
var grep, results;
try {
grep = new RegExp("gr[");
results = grep.exec('bob went to town');
}
catch(e) {
alert(e);
}
alert('If you can see this then the script kept going');
解决方案4
2 2008-09-23 15:37:29
putting the RegExp initialization inside the try/catch will work (just tested in FireFox) 将RegExp初始化放在try / catch中将起作用（仅在FireFox中测试）
var grep, results;
try
{
grep = new RegExp("gr["); // your user input here
}
catch(e)
{
alert("The RegExpr is invalid");
}
// do your stuff with grep and results
Escaping here is not the solution. 逃避这里不是解决方案。 Since the purpose of this snippet is to actually test a user-generated RegExpr, you will want to catch [ as an unclosed RegExpr container. 由于此代码段的目的是实际测试用户生成的RegExpr，因此您需要捕获[作为未关闭的RegExpr容器。
解决方案5
1 2008-09-23 12:38:15
your RegExp doesn't close the [ 你的RegExp没有关闭[
In my FireFox, it never returns from the constructor -- looks like a bug in the implementation of RegExp, but if you provide a valid expression, it works 在我的FireFox中，它永远不会从构造函数返回 - 看起来像是RegExp实现中的一个错误，但是如果你提供一个有效的表达式，它就有效
解决方案6
0 2008-09-23 12:54:04
One option is to validate the user-generated expressions. 一种选择是验证用户生成的表达式。 That is; 那是; escape characters that you know will stall your script. 你知道的转义字符会使你的脚本失效。
声明:本站的技术帖子网页，遵循CC BY-SA 4.0协议，如果您需要转载，请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.