请问,1、用javascript怎么可以判断单选按钮是否选中,如果选中怎么可以得到选中的值,
2、怎样可以判断复选框是否选中,并且最多可以选择2项,如果选中,得到选中的值,多谢啦!
比如代码如下:<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<script type="text/javascript">
function saveRadio(){
alert("radio");
}
function saveCheck(){
alert("check");
}
</script>
</head>
<body>
<div>
选项1<input name="radio1" type="radio" value="01" />
选项2<input name="radio1" type="radio" value="02" />
选项3<input name="radio1" type="radio" value="03" />
</div>
<div>
<input type="button" value="保存" onclick="saveRadio()" />
</div>
<div>
选项1<input type="checkbox" name="checkbox1" value="01" />
选项2<input type="checkbox" name="checkbox1" value="02" />
选项3<input type="checkbox" name="checkbox1" value="03" />
选项4<input type="checkbox" name="checkbox1" value="04" />
</div>
<div>
<input type="button" value="保存" onclick="saveCheck()" />
</div>
</body>
</html>
2、怎样可以判断复选框是否选中,并且最多可以选择2项,如果选中,得到选中的值,多谢啦!
比如代码如下:<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<script type="text/javascript">
function saveRadio(){
alert("radio");
}
function saveCheck(){
alert("check");
}
</script>
</head>
<body>
<div>
选项1<input name="radio1" type="radio" value="01" />
选项2<input name="radio1" type="radio" value="02" />
选项3<input name="radio1" type="radio" value="03" />
</div>
<div>
<input type="button" value="保存" onclick="saveRadio()" />
</div>
<div>
选项1<input type="checkbox" name="checkbox1" value="01" />
选项2<input type="checkbox" name="checkbox1" value="02" />
选项3<input type="checkbox" name="checkbox1" value="03" />
选项4<input type="checkbox" name="checkbox1" value="04" />
</div>
<div>
<input type="button" value="保存" onclick="saveCheck()" />
</div>
</body>
</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<script type="text/javascript">
function saveRadio(){
var arr= document.getElementsByName("radio1");
var v="";
for(var i=0;i<arr.length;i++){
if(arr[i].checked) {v = arr[i].value;break;}
}
alert(v);
}
function saveCheck(){
var arr= document.getElementsByName("checkbox1");
var v="";
for(var i=0;i<arr.length;i++){
if(arr[i].checked) v += arr[i].value + ",";
}
if(v!="") v = v.substr(0,v.length-1);
alert(v);
}
</script>
</head>
<body>
<div>
选项1<input name="radio1" type="radio" value="01" />
选项2<input name="radio1" type="radio" value="02" />
选项3<input name="radio1" type="radio" value="03" />
</div>
<div>
<input type="button" value="保存" onclick="saveRadio()" />
</div>
<div>
选项1<input type="checkbox" name="checkbox1" value="01" />
选项2<input type="checkbox" name="checkbox1" value="02" />
选项3<input type="checkbox" name="checkbox1" value="03" />
选项4<input type="checkbox" name="checkbox1" value="04" />
</div>
<div>
<input type="button" value="保存" onclick="saveCheck()" />
</div>
</body>
</html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<script type="text/javascript">
function saveRadio()
{
var radio = document.getElementsByName("radio1");
var b = true;
for(var i = 0; i < radio.length; i++)
{
if(radio[i].checked)
{
alert(radio[i].value);
b = false;
break;
}
}
if(b) alert("什么都没选!");
}
function saveCheck()
{
var check = document.getElementsByName("checkbox1");
var n = 0, s = "";
for(var i = 0; i < check.length; i++)
{
if(check[i].checked)
{
n++;
s += "\r\n" + check[i].value;
}
}
switch(n)
{
case 0: s = "什么都没选!"; break;
case 1:
case 2: break;
default: s = "只能选择两项!"; break;
}
alert(s);
}
</script>
</head>
<body>
<div>
选项1<input name="radio1" type="radio" value="01" />
选项2<input name="radio1" type="radio" value="02" />
选项3<input name="radio1" type="radio" value="03" />
</div>
<div>
<input type="button" value="保存" onclick="saveRadio()" />
</div>
<div>
选项1<input type="checkbox" name="checkbox1" value="01" />
选项2<input type="checkbox" name="checkbox1" value="02" />
选项3<input type="checkbox" name="checkbox1" value="03" />
选项4<input type="checkbox" name="checkbox1" value="04" />
</div>
<div>
<input type="button" value="保存" onclick="saveCheck()" />
</div>
</body>
</html>
function saveCheck()
{
var check = document.getElementsByName("checkbox1");
var n = 0, s = "";
var LIMIT = 2;
for(var i = 0; i < check.length; i++)
{
if(check[i].checked)
{
n++;
if(n > LIMIT) break;
s += "\r\n" + check[i].value;
}
}
if(n == 0)
s = "什么都没选!"
else
if(n > LIMIT)
s = "只能选择" + LIMIT.toString(10) + "项!"; alert(s);
}