Javascript 文本区域的验证无效_Javascript

Javascript 文本区域的验证无效

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Javascript 文本区域的验证无效,javascript,Javascript,我已经开发了一个表单来获取用户输入和文本区域，我希望避免用户键入特殊字符下面是我用于验证的表单和函数的代码。问题是，即使在使用验证之后，它也会接受用户输入的特殊字符。我找不到哪里出了问题。请帮帮我提前谢谢 index.jsp <%@page contentType="text/html" pageEncoding="UTF-8"%> <%@page language="java" session="true" %> <!DOCTYPE html> &l

我已经开发了一个表单来获取用户输入和文本区域，我希望避免用户键入特殊字符

下面是我用于验证的表单和函数的代码。问题是，即使在使用验证之后，它也会接受用户输入的特殊字符。我找不到哪里出了问题。请帮帮我

提前谢谢

index.jsp

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@page language="java" session="true" %> 

<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <script type="text/javascript" src="scripts/scripts.js"></script>

    <title>Untitled Document</title>
</head>
<body>
<form name = "MyForm" action="SubmitUser" method ="post" onsubmit="validate()">

<textarea rows="6" cols="150" name="comment" value="">
                </textarea>


<input type = "submit" name ="sub" value="Submit">

  </body>
</html>

下面是scripts.js

function validate() {
    var iChars = "!@#$%^&*()+=-[]\\\';,./{}|\":<>?";
    for (var i = 0; i < document.MyForm.comment.value.length; i++) {
        if (iChars.indexOf(document.MyForm.comment.value.charAt(i)) != -1) {
            alert ("This Field has special characters. \nSpecial Characters are not allowed");
            return false;
        }
    }
}

您想使用RegExp

var iChars = new RegExp(/[@!#$%^&*()+=\[\]\-\\\';,./{}|\":<>?]/)
var x = "AB@"
iChars.test(x) // true

有关regexp的详细信息，请参见。您可以使用：

\W匹配任何非单词字符

然后你的res结果是一个匹配字符串的数组，只要测试res.length>0，输入的注释就无效

那么您的功能将是：

function validate(){
  var comment = document.MyForm.comment.value; 
  var res = comment.match(/\W/);
  if(res.length>0) alert ("This Field has special characters. \nSpecial Characters are not allowed");
}

您没有停止表单的提交事件。要停止正常流程，您可以修改以下代码逻辑：

<form name = "MyForm" action="SubmitUser" method ="post">

<textarea rows="6" cols="150" name="comment" value="">
                </textarea>


<input type = "button" name ="sub" value="Submit" onclick="validate()">

并将javascript修改为：

function validate(){
   var iChars = "!@#$%^&*()+=-[]\\\';,./{}|\":<>?";
   for (var i = 0; i < document.MyForm.comment.value.length; i++) {
     if (iChars.indexOf(document.MyForm.comment.value.charAt(i)) != -1) {
       alert ("This Field has special characters. \nSpecial Characters are not allowed");
     return false;
    }
  document.MyForm.submit();
}

希望您具有进行验证的逻辑

<form name = "MyForm" action="SubmitUser" method ="post">

<textarea rows="6" cols="150" name="comment" value="">
                </textarea>


<input type = "button" name ="sub" value="Submit" onclick="validate()">

function validate(){
   var iChars = "!@#$%^&*()+=-[]\\\';,./{}|\":<>?";
   for (var i = 0; i < document.MyForm.comment.value.length; i++) {
     if (iChars.indexOf(document.MyForm.comment.value.charAt(i)) != -1) {
       alert ("This Field has special characters. \nSpecial Characters are not allowed");
     return false;
    }
  document.MyForm.submit();
}