Web开发笔记(6)：js function的简单使用

来源：互联网发布：mac残留windows软件编辑：程序博客网时间：2024/05/27 06:54

俗话说，不处理响应的javascript不是真正的javascript

学习一下function的响应，基于上一节的简单界面，编写简单的function函数，用以检查输入，并触发响应

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!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">
<title>Student Management System</title>
<script type="text/javascript" language="javascript" src="js/welcome.js"></script>
</head>
<body>
<form name="infoForm" action="" method="post">
Name:<input type="text" name="username" value="input username"><br>
Password:<input type="password" name="password" value="input password"><br>
Sex:<input type="radio" name="sex" value="Male">Male
<input type="radio" name="sex" value="Female">Female<br>
Grade:<select>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
</select><br>
Teacher:<input type="checkbox" name="teacher" value="Tom">
<input type="checkbox" name="teacher" value="Andy">
<input type="checkbox" name="teacher" value="Janson">
</form>
<input type="submit" value="Submit" onclick="return doCheck()">
<input type="reset" value="Reset">

<script type="text/javascript">
function doCheck() {
if(infoForm.username.value == "") {
alert("Input value cannot be empty, pls check");
return false;
}
for(var index=0; index<arguments.length; index++) {
if(arguments[i] == "") {
alert("Input value cannot be empty, please check");
return false;
}
}
return true;
}
</script>

</body>
</html>

这里没有搞懂function传参，和独立js文件的编写，后续补充

执行结果如下：

0 0