如果字符串包含不在 RegEx 中的字符，则 Javascript RegEx 返回
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Javascript RegEx to return if string contains characters that are NOT in the RegEx
提问by Luke Shaheen
I have a user created string. I am only allowing the characters A-Z, a-z, 0-9, -,and _
我有一个用户创建的字符串。我只允许字符A-Z, a-z, 0-9, -,和_
Using JavaScript, how can I test to see if the string contains characters that are NOT these? If the string contains characters that are not these, I want to alert the user that it is not allowed.
使用 JavaScript，如何测试字符串是否包含非这些字符？如果字符串包含不是这些字符，我想提醒用户这是不允许的。
What Javascript methods and RegEx patterns can I use to match this?
我可以使用哪些 Javascript 方法和 RegEx 模式来匹配它？
回答by Donut
You need to use a negated character class. Use the following pattern along with the matchfunction:
您需要使用否定字符类。将以下模式与match函数一起使用：
[^A-Za-z0-9\-_]
Example:
例子：
var notValid = 'This text should not be valid?';
if (notValid.match(/[^A-Za-z0-9\-_]/))
alert('The text you entered is not valid.');
回答by Ray Toal
This one is straightforward:
这个很简单：
if (/[^\w\-]/.test(string)) {
alert("Unwanted character in input");
}
The idea is if the input contains even ONE disallowed character, you alert.
这个想法是，如果输入甚至包含一个不允许的字符，你就会发出警报。
