代码示例:(标识:js_number_max_undefined)
<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Number 属性</h1>

<p>在变量或值上使用 Number 属性将返回 undefined:</p>

<p id="demo"></p>

<script>
let x = 6;
document.getElementById("demo").innerHTML = x.MAX_VALUE;
</script>

</body>
</html>
运行结果: