{"html":"<!DOCTYPE html>\n<html lang=\"en\">\n    <head>\n        <meta charset=\"UTF-8\">\n    </head>\n    <body>\n        \n        <script>\n            const _flatten = arr => {\n                // 补全代码\n                return arr.reduce((prev, cur) => {\n                    return prev.concat(Array.isArray(cur) ? _flatten(cur) : cur)\n                }, [])\n            }\n        </script>\n    </body>\n</html>","css":"","js":""}