Javascript验证：阻止特殊字符

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如何限制用户在文本框中输入特殊字符。我只想输入数字和字母（输入/粘贴）。

How can I restrict users from entering special characters in the text box. I want only numbers and alphabets to be entered ( Typed / Pasted ).

任何样品？

推荐答案

你有两种方法：

检查按键事件。如果用户按下特殊字符键，请将其停在那里

检查onblur事件：当输入元素失去焦点时，验证其内容。如果该值无效，请在该输入框旁边显示谨慎的警告。

我建议使用第二种方法，因为它不那么刺激。还记得检查 onpaste 。如果你只使用按键那么我们可以复制并粘贴特殊字符，所以使用 onpaste 也限制粘贴特殊字符

I would suggest the second method because its less irritating. Remember to also check onpaste . If you use only keypress Then We Can Copy and paste special characters so use onpaste also to restrict Pasting special characters

此外，我还建议您重新考虑是否确实要阻止用户输入特殊字符。因为很多人的密码都有$，＃，@和*。

Additionally, I will also suggest that you reconsider if you really want to prevent users from entering special characters. Because many people have $, #, @ and * in their passwords.

我认为这可能是为了防止SQL注入;如果是这样：你处理服务器端的检查更好。或者更好的是，转义值并将它们存储在数据库中。

I presume that this might be in order to prevent SQL injection; if so: its better that you handle the checks server-side. Or better still, escape the values and store them in the database.