<input type="radio" id="radioId" value="1" >
选中单选框JS代码：
var target = document.getElementById("radioId")
target.checked = true
附完整代码：
<!DOCTYPE html>
<!--STATUS OK-->
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=Edge" />
<meta http-equiv="content-type" content="text/htmlcharset=gbk" />
<meta property="wb:webmaster" content="3aababe5ed22e23c" />
<meta name="referrer" content="always" />
<title>demo</title>
</head>
<body>
<input type="radio" value="radio1" id="radio1" name="radio"/><label for="radio1">RADIO 1</label>
<input type="radio" value="radio2" id="radio2" name="radio"/><label for="radio2">RADIO 2</label>
<input type="radio" value="radio3" id="radio3" name="radio"/><label for="radio3">RADIO 3</label>
<input type="radio" value="radio4" id="radio4" name="radio"/><label for="radio4">RADIO 4</label>
<br/><br/>
<button onclick="selectRadio('radio1')">选中radio1</button>
<button onclick="selectRadio('radio2')">选中radio2</button>
<button onclick="selectRadio('radio3')">选中radio3</button>
<button onclick="selectRadio('radio4')">选中radio4</button>
<br/>
<br/>
</body>
<script type="text/javascript">
function selectRadio(radioId) {
var target = document.getElementById(radioId)
target.checked = true
}
</script>
</html>
这样：
<!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/htmlcharset=utf-8" />
<title>JQuery radio</title>
<script type="text/javascript" language="javascript" src="JavaScript/jquery-1.6.1.min.js" ></script>
<script type="text/javascript">
$(function () {
$("input").click(function () {
if ($(this).attr("checked")) {
alert("选中了")
}
})
})
</script>
</head>
<body>
<input type="radio"/>
</body>
</html>
扩展资料：注意事项
<form>
<input type="radio" id="radio1" />
<input type="button" οnclick="check()" value="选中" />
<input type="button" οnclick="uncheck()" value="取消" />
</form>
function check() {
//被选中
document.getElementById("radio1").checked = true
//被选中时，可以执行的方法
if(document.getElementById("radio1").checked == true){
console.log('==')
}
}
function uncheck() {
//不选中
document.getElementById("radio1").checked = false
//不被选中时，可以执行的方法
if(document.getElementById("radio1").checked == false){
console.log('++')
}
}
