HTML表单的Java验证无效
[英]Javascript validation for html form not working
问题描述
I'm trying to make a working javascript validator for an HTML form for an assessment, I have gotten the lecturer to help me originally, however they could not solve the issue. 
我正在尝试为HTML表单制作一个可工作的javascript验证器以进行评估，我最初得到了讲师的帮助，但是他们无法解决问题。 The validation works until I add another input to validate then it completely stops working. 验证有效，直到我添加另一个输入进行验证，然后完全停止工作。 I am new to javascript, i have never worked with it before. 我是javascript新手，以前从未使用过它。
I have tried rebuiling the validator and order form completely multiple times. 我已经尝试过多次重新建立验证程序和订购表。 I have reviewed the code multiple times to no avail. 我已多次审查该代码，但无济于事。
function validateForm() { var x = document.forms["myForm"]["fname"].value; if (x == " ") { alert("Name must be filled out"); return false; } var y = document.forms["myForm"]["mname"].value; if (y == " ") { alert("middle name must be filled out"); return false; } }
<script src="Validator.js"></script> <form name="myForm" onsubmit="return validateForm()" action="OrderConfirmed.htm" method="post"> Name: <input type="text" name="fname" value=" "> Middle Name: <input type="text" name="mname" value=" "> <input type="submit" value="Submit"> </form>
The expected result is that when the form is submitted but a field is empty a message (dialog box) should be displayed telling the user which input is not filled in. 预期结果是，在提交表单但字段为空时，将显示一条消息（对话框），告诉用户未填写哪个输入。
1 个解决方案
解决方案1
1 已采纳 2019-06-15 15:15:03
You could solve it by using 'event.preventDefault'. 您可以使用“ event.preventDefault”解决它。 (But your code should work too...) Here is example code: （但是您的代码也应该工作...）这是示例代码：
<html> <head> </head> <body> <form name="myForm" onsubmit="validateForm(event)"> Name: <input type="text" name="fname" value=" "> Middle Name: <input type="text" name="mname" value=" "> <input type="submit" value="Submit"> </form> <script type="text/javascript"> function validateForm(e) { var x = document.forms["myForm"]["fname"].value; if (x == " ") { e.preventDefault(); alert("Name must be filled out"); return false; } var y = document.forms["myForm"]["mname"].value; if (y == " ") { e.preventDefault(); alert("middle name must be filled out"); return false; } } </script> </body> </html>
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.