{"html":"<!DOCTYPE html>\n<html>\n\n<head>\n    <meta charset=\"UTF-8\">\n    <style>\n       /* 填写样式 */\n    </style>\n</head>\n\n<body>\n    <!-- 填写标签 -->\n    <script type=\"text/javascript\">\n        // 填写JavaScript\n        function _instanceof(left,right) {\n            let L = left.__proto__\n            const R = right.prototype\n            while(true){\n                if(L === R){\n                    return true\n                }\n                if(L === null){\n                    return false\n                }\n                L = L.__proto__\n            }\n}\n    </script>\n</body>\n\n</html>","css":"","js":""}

通过原型链的查找来判断，也是instanceof实现的原理。