为什么无参函数里面不能写strlen（name）+1？

Question

class Person
{
private:
    char name[20];
    char sex;
    int age;
    char* addr;
public:
    Person()
    {
        strcpy_s(name, strlen（name）+1，"张三");
        sex = 'x';
        age = 0;
        addr = new char[20];
        addr[0] = '\0';   
    }
    Person(char* n, int age, char sex, char* addr)
    {
        strcpy_s(this->name, strlen(n) + 1, n);
        this->age = age;
        this->sex = sex;
        this->addr = new char[strlen(addr) + 1];
        strcpy_s(this->addr, strlen(addr) + 1, addr);
    }
    Person(Person& p)
    {
        strcpy_s(this->name, strlen(name + 1), p.name);
        this->age = p.age;
        this->sex = p.sex;
        addr = new char[strlen(p.addr) + 1];
        strcpy_s(this->addr, strlen(p.addr) + 1, p.addr);
    }
    ~Person()
    {
        delete[] addr;
    }
    void ShowMe();
};
void Person::ShowMe()
{
    cout << "姓名为：" << name << ",年龄为：" << age << ",性别为：" << sex << "，地址为：" << addr << endl;
}
int main()
{
    Person person1;
    person1.ShowMe();
    Person person2((char*)"小丽", 19, 'm', (char*)"中国广东省深圳市");
    person2.ShowMe();
}

Answer 1

strcpy_s(name, strlen（name）+1，"张三");
name在赋值之前，是个空字符串，strlen得到的是0，或者是个垃圾值，因为name数组没有初始化为空
改为
strcpy_s(name,sizeof(name),"张三");