number
它只接受数值。 step属性指定精度，默认为1。
例子 (Example)
<!DOCTYPE HTML>
<html>
<body>
<form action = "/cgi-bin/html5.cgi" method = "get">
Select Number : <input type = "number" min = "0" max = "10" step "1"
value = "5" name = "newinput" />
<input type = "submit" value = "submit" />
</form>
</body>
</html>
