Javascript表单验证提交错误 [英] Javascript form validation submit errors

问题描述

从我在网络上看到的所有内容看来，下面的代码应该做以下事情（这是我的期望）：

• 如果电子邮件（aid）与正则表达式不匹配，则显示警告消息并返回false


• 如果密码（pass）为空，则显示警告消息并返回false


• 如果两个条件都通过验证，请提交表单

Javascript如下所示： / p>

  function validate（）{
 var email = document.getElementById（'aid'）。value; 
 var pass = document.getElementById（'apw'）。value; 
 var emailPattern = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-ZA-Z]{2,4} $ /; 
 if（！emailPattern.test（email））{
 alert（不是有效的电子邮件地址）; 
返回false; 
} 
 if（pass == null || pass ==）{
 alert（Password is blank）; 
返回false; 
} 
返回true; 
} 
  

标签的开头如下：

 < form action =choose.phponsubmit =validate（）;方法= POST > 
  

我遇到的问题是，当点击提交按钮时，会弹出警告消息，但是然后choose.php加载到浏览器中。如果错误条件被触发，我希望脚本保留在页面上，直到两个条件都通过。 你需要将您的onSubmit更改为 onSubmit =return validate（）;。这样当它返回false时，表单不会被提交。现在它只是调用validate（）函数并继续提交表单

From everything I've seen around the net, it appears that the following code should do the following (and this is my expectation):

• If the email ("aid") does not match the regex, show alert message and return false
• If the password ("pass") is blank, show alert message and return false
• If both conditions pass validation submit the form

The Javascript is as follows:

function validate() {
var email = document.getElementById('aid').value;
var pass = document.getElementById('apw').value;        
var emailPattern = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;  
if (!emailPattern.test(email)) {
    alert("Not a valid email address");
    return false;
}
if (pass == null || pass == "") {
    alert("Password is blank");
    return false;   
}
return true;
}

The opening for tag is as follows:

<form action="choose.php" onsubmit="validate();" method="post">

The problem I'm having is that when the submit button is clicked, the alert message will pop up, but then choose.php is loaded in the browser. I want the script, if the error conditions are triggered, to remain on the page until both conditions are passed.

解决方案

You need to change your onSubmit to onSubmit="return validate();". This way when it returns false, the form doesn't get submitted. Right now it just calls the validate() function and continues on with submitting the form

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