02instanceof.html

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        function myInstanceof(left, right) {
            left = left.__proto__;
            while (true) {
                if (left === null) return false
                else if (left === right.prototype) return true
                left = left._proto_
            }

        }

    </script>
</body>

</html>