示例：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body >
<form>
用户名： <input type="text" id="username">
密码：<input type="password" id="pwd"><br/>
兴趣：音乐<input type="checkbox" name="interest" checked id="music">
电视<input type="checkbox" name="interest" id="tv" checked>
足球<input type="checkbox" name="interest" id="football"><br/>
城市：<select name="city" multiple>
<option id="beijing" selected >北京</option>
<option id="shanghai" selected>上海</option>
<option id="ningbo" >宁波</option>
</select>
性别：男<input type="radio" name="sex" id="man" checked>
女<input type="radio" name="sex" id="woman">
<input type="button" id="button">
<input type="image" id="image">
<input type="file" id="file">
<input type="reset" id="reset" disabled>
<input type="submit" id="submit">
</form>
<script src="http://apps.bdimg.com/libs/jquery/1.6.4/jquery.js"></script>
<script>
var input=$(":input")
var text=$(":text")
var password=$(":password")
var radio=$(":radio")
var checkbox=$(":checkbox")
var submit=$(":submit")
var reset=$(":reset")
var button=$(":button")
var image=$(":image")
var file=$(":file")
var enabled=$(":enabled")
var disabled=$(":disabled")
var selected=$(":selected")
var checked=$(":checked")
console.log(input)
console.log(text)
console.log(password)
console.log(radio)
console.log(checkbox)
console.log(submit)
console.log(reset)
console.log(button)
console.log(image)
console.log(file)
console.log(enabled)
console.log(disabled)
console.log(selected)
console.log(checked)
</script>
</body>
</html>
运行结果：
