验证
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>demo</title>
</head>
<body>
<script>
function myFunction() {
try {
var x = document.getElementById("demo").value;
if (x == "") throw "值为空";
if (isNaN(x)) throw "不是数字";
if (x > 10) throw "太大";
if (x < 5) throw "太小";
} catch (err) {
var y = document.getElementById("mess");
y.innerHTML = "错误：" + err + "。";
}
}
</script>
<h1>验证数字</h1>
<p>
请输入5到10之间的数字：
</p>
<input id="demo" type="text">
<button type="button" onclick="myFunction()">测试输入值</button>
<p id="mess"></p>
</body>
</html>