Javascript复选框表单验证 [英] Javascript checkbox form validation
问题描述
我尝试将此链接用作我的资源： http：//www.w3schools。 com / js / js_form_validation.asp
我理解它如何适用于文本框，但是如何让它检测复选框的表单验证？例如，如果我有一个排列着复选框的页面（所有页面都具有相同的名称值），我想确保至少有一个框被选中...我该怎么做？如果复选框未被选中，以及javascript应该如何捕获，我对发送post请求有点困惑。感谢您。
编辑----
得到它的工作，以下是未来人员的一些代码：
<！DOCTYPE html>
< html>
< head>
< script type =text / javascript>
函数Validate（）{
if（！validateForm（））{
alert（Something happened）;
返回false;
返回true
函数validateForm（）
{
var c = document.getElementsByTagName（'input'）;
for（var i = 0; i< c.length; i ++）{
if（c [i] .type =='checkbox'）
{
if（c [i] .checked）{return true}
}
}
return false;
}
< / script>
< / head>
< body>
< form name =myFormaction =demo_form.asponsubmit =return Validate（）method =post>
值：< input type =checkboxname =fnamevalue =value>
Value2：< input type =checkboxname =fnamevalue =value2>
...<这里有更多箱子>
< input type =submitvalue =提交>
< / form>
< / body>
< / html>
下面是一个例子，可以在此页面中进行测试：
复选框）;返回false; } return true} function validateForm（）{var c = document.getElementsByTagName（'input'）; for（var i = 0; i< c.length; i ++）{if（c [i] .type =='checkbox'）{if（c [i] .checked）{return true}}} return false;}
< form name =myFormaction =demo_form .asponsubmit =return Validate（）method =post>选项1：< input type =checkboxname =option1value =1>< br / < input type =checkboxname =option2value =2>< br />< input type =submitvalue =Submit Form>< / form>
I'm trying to use this link as my resource: http://www.w3schools.com/js/js_form_validation.asp
I understand how it works for textboxes, but how do you make it detect form validation for checkboxes? For example, if I have a page lined with checkboxes (all with the same "name" value), I want to make sure that at least one of the boxes is checked... How do I do this? I'm a little confused about what post request is sent if a checkbox is not checked, and how javascript should catch it. Thank you.
Edit----
Got it to work, here's some code for future people:
<!DOCTYPE html>
<html>
<head>
<script type="text/javascript">
function Validate(){
if(!validateForm()){
alert("Something happened");
return false;
}
return true
}
function validateForm()
{
var c=document.getElementsByTagName('input');
for (var i = 0; i<c.length; i++){
if (c[i].type=='checkbox')
{
if (c[i].checked){return true}
}
}
return false;
}
</script>
</head>
<body>
<form name="myForm" action="demo_form.asp" onsubmit="return Validate()" method="post">
Value: <input type="checkbox" name="fname" value="value">
Value2: <input type="checkbox" name="fname" value="value2">
...<more boxes here>
<input type="submit" value="Submit">
</form>
</body>
</html>
Here is an example that does what you are asking and can be tested within this page:
function Validate(){
if(!validateForm()){
alert("You must check atleast one of the checkboxes");
return false;
}
return true
}
function validateForm()
{
var c=document.getElementsByTagName('input');
for (var i = 0; i<c.length; i++){
if (c[i].type=='checkbox')
{
if (c[i].checked){return true}
}
}
return false;
}
<form name="myForm" action="demo_form.asp" onsubmit="return Validate()" method="post">
Option 1: <input type="checkbox" name="option1" value="1"><br />
Option 2: <input type="checkbox" name="option2" value="2"><br />
<input type="submit" value="Submit Form">
</form>
这篇关于Javascript复选框表单验证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！
