深拷贝

深拷贝

function deepCopy(target, copys) {
    const isObject = target => target instanceof Object;
    if (isObject(target) && isObject(copys)) {
        // 如果要拷贝的对象是个空对象直接返回原对象
        if (!Object.keys(copys).length) {
            return target;
        }

        let val;
        for (let key in copys) {
            val = copys[key];
            if (!isObject(val)) {
                target[key] = val;
                continue;
            }
            // 创建对应类型的临时对象, 然后拷贝对象中的属性然后赋值
            const temp = new copys.constructor;
            deepCopy(temp, val);
            target[key] = temp;
        }
        return target;
    }
    console.warn("the parameters is must be object");
}

let o1 = {
    name: 'jason',
    age: 10,
};
let o2 = {
    sex: 1,
    friends: ['alex', 'jerry'],
    pet: { type: 'cat', name: 'tom' },
    birthday: new Date(),
}
o1 = deepCopy(o1, o2);
console.log(o1);
console.log(o2);