深拷贝

    let json = [1, 2, 3, 4, 5, 6, 7, 8, 9, {
            name: 111,
            age: 18
        },
        [1, 2, 3, 4]
    ];

    function deepCopy(obj) {
        if (typeof obj == "object") {
            var res = obj.constructor == Array ? [] : {};
            for (let i in obj) {
                res[i] = typeof obj[i] == "object" ? deepCopy(obj[i]) : obj[i];
            }
        } else {
            var res = obj;
        }
        return res;
    }
    console.log(deepCopy(json));