警报未在JS中显示 [英] alert not displaying in JS
本文介绍了警报未在JS中显示的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
警报无法正常工作！我不知道为什么...
我正在尝试评估客户端的表单。我已经尝试过getElementsById，getElementsByName。
我要去哪里错了？
我确定控制流通过validate（）
，其中立即显示一个validate方法内的警报语句！
alert is not working as expected! i don't know why... I am trying to evaluate a form on client side. I have tried getElementsById, getElementsByName. Where am i going wrong? I am sure the flow of control goes through validate() an alert statement immediately inside validate method is being displayed!
这是我的代码：
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1" errorPage="Error.jsp"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<script type="text/javascript">
function validate() {
var uname = document.getElementById("uname").value;
var email = document.getElementById("email").value.indexof('@');
var pass = document.getElementById("pass").value;
var rpass = document.getElementById("rpass").value;
submitOK = true;
if (uname.length == 0) {
alert("Username cannot be empty")
submitOK = false;
}
if (email == -1) {
alert("Not a valid email");
submitOK = false;
}
if (pass.length === 0) {
alert("Password cannot be empty");
submitOK = false;
}
if (pass != rpass) {
alert("passwords don't match");
submitOK = false;
}
return submitOK;
}
</script>
<title>Register</title>
</head>
<body>
<h1>Register</h1>
<br />
<form action="RegInt.jsp" method="post" onsubmit="return validate()">
Enter UserName : <input type="text" name="uname" id="uname" value='${ param.uname}'placeholder="Enter Name" ><br/><br/>
Enter Email: <input type="email" name="email" id = "email" value='${param.email}'placeholder="Enter Email"><br/><br/>
Enter Password: <input type="password" name="pass" id = "pass" value='${param.pass}'placeholder="Enter password"><br/><br/>
Repeat Password: <input type="password" name="rpass" id = "rpass" value='${param.rpass}'placeholder="Repeat Password"/><br/>
<br/><br/>
<input type="submit"/>
</form>
<h4>${errorMsg}</h4>
</body>
</html>
推荐答案
- 警惕和indexOf！
- getElementById为奇数
- submitOK = false将SubmitOK设置为true，因为非空字符串是真实的。使用
submitOK = false - 当您问问题时您没有返回SubmitOK
- Spelling of alret and indexOf !
- getElementById is singular
- submitOK="false" sets submitOK to true since a non-empty string is truthy. use
submitOK=false - you did not return submitOK when you asked the question
function validate() {
var uname = document.getElementById("uname").value;
var email = document.getElementById("email").value.indexOf('@');
var pass = document.getElementById("pass").value;
var rpass = document.getElementById("rpass").value;
submitOK = true;
if (uname.length == 0) {
alert("Username cannot be empty")
submitOK = false;
}
if (email == -1) {
alert("Not a valid email");
submitOK = false;
}
if (pass.length === 0) {
alert("Password cannot be empty");
submitOK = false;
}
if (pass != rpass) {
alert("passwords don't match");
submitOK = false;
}
return submitOK;
}
<h1>Register</h1>
<br />
<form action="RegInt.jsp" method="post" onsubmit="return validate()">
Enter UserName :
<input type="text" name="uname" id="uname" value='${ param.uname}' placeholder="Enter Name">
<br/>
<br/>Enter Email:
<input type="email" name="email" id="email" value='${param.email}' placeholder="Enter Email">
<br/>
<br/>Enter Password:
<input type="password" name="pass" id="pass" value='${param.pass}' placeholder="Enter password">
<br/>
<br/>Repeat Password:
<input type="password" name="rpass" id="rpass" value='${param.rpass}' placeholder="Repeat Password" />
<br/>
<br/>
<br/>
<input type="submit" />
</form>
这篇关于警报未在JS中显示的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
