html5表单实现简单计算器
<!DOCTYPE html>
<html>
<head>
<title>this is a html page</title>
</head>
<body>
<form oninput="res.value = n1.valueAsNumber * n2.valueAsNumber">
<input type="number" id="n1"> x
<input type="number" id="n2"> =
<output id="res" name="res" />
</form>
</body>
</html>