可能就自己能看懂 ,
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<script type="text/javascript" src="js/jquery-1.8.2.min.js" ></script>
<script type="text/javascript">
function aa(){
//alert("a");
/*var h=$("h1").html();
alert(h)*/
//$("body").html("<p>aaaa</p>");
//$("#single").val("Single2");
//$("select[name='sel']").val("Single2")
//$("#multiple").val(["Multiple2", "Multiple3"]);
//$("input").val(["百合", "radio1"]);
//下拉框alert($("#single").val())选中后打印
//$("input[value='check1']").attr("checked",true)
//$("input[value='radio1']").attr("checked",true)
//$("#text").focus();
/*var a=$("input[name=radio]:checked").val()
alert(a)*/
//$("input[name='radio'][value='radio1']").attr("checked",true)
//$(":radio").val(["radio1"]);
/*var a="啦啦1,百合2,3";
var aa=a.split(",");
for (var i in aa) {
$(":checkbox[value="+aa[i]+"]").attr("checked",true)
}*/
//必须放一个数组
/*var a=["啦啦1","百合2","3"];
$("input[name='check']").val(a);*/
//$("input[name='check']").val(["啦啦1","百合2"])
//$("input").val(["百合", "radio1"]);
//$(":radio").val(["radio1"]);
/*$(":checkbox[name='check']:checked").map(function(n){
alert($(this).val()+n);
})*/
/*不用拿到map也可以打印
* var a=$("input:checked");
for(var i in a){
alert($(a[i]).val())
}*/
/*把所有checked的值放到a中
* var a=$("input:checked").map(function(){
return $(this).val();
}).get().join(", ")
alert(a);*/
//全选$(":checkbox[name='check']").attr("checked",true);
/*反选$(":checkbox[name='check']").map(function(){
if($(this).is(":checked")){
$(this).attr("checked",false);
//$(this).val([]);
}else{
$(this).attr("checked",true);
}
})*/
//这个是按键后触发事件$("#p").append("123");
/*一定不能用id去选择CheckBox 和radio 因为 id只会选择一个;
* $("#ckeck").attr("checked",true)*/
}
</script>
<body>
<h1>啦啦啦啦</h1><br />
<select id="single" name="sel">
<option>Single</option>
<option>Single2</option>
<option value="1" >Single3</option>
</select><br />
<select id="multiple" multiple="multiple">
<option selected="selected">Multiple1</option>
<option>Multiple2</option>
<option selected="selected">Multiple3</option>
</select><br/>
<input type="checkbox" name="check" id="ckeck" value="啦啦1"/> 啦啦
<input type="checkbox" name="check" id="ckeck" value="百合2"/> 百合
<input type="checkbox" name="check" id="ckeck" value="3"/> 搞基
<input type="checkbox" name="check" id="ckeck" value="4"/> 乱伦
<br />
<input type="radio" name="radio" id="radio" value="radio1"/> radio1
<input type="radio" name="radio" id="radio" value="radio2"/> radio2
<br />
<p id="p" >aa</p>
<input type="text" id="text" name="tt" onkeydown="aa()" />
<button onclick="aa()">点我</button>
<div style="display: none;"></div>
</body>
</html>