[Structure] Several common ways to write structures in Cpp

1. Define and declare structure variables:

struct Date {
    int year;
    int month;
    int day;
};

int main() {
    Date date; // 声明并定义了一个Date类型的变量date
    date.year = 2023;
    date.month = 9;
    date.day = 11;
    return 0;
}

2. Use typedef to declare the structure type and define variables:

typedef struct {
    int year;
    int month;
    int day;
} Date;

int main() {
    Date date; // 声明并定义了一个Date类型的变量date
    date.year = 2023;
    date.month = 9;
    date.day = 11;
    return 0;
}

3. Separate structure definition and declaration:

struct Date {
    int year;
    int month;
    int day;
};

int main() {
    struct Date date; // 声明并定义了一个Date类型的变量date
    date.year = 2023;
    date.month = 9;
    date.day = 11;
    return 0;
}

4. Use structure pointers:

struct Date {
    int year;
    int month;
    int day;
};

int main() {
    struct Date *datePtr; // 声明了一个Date类型的指针变量datePtr
    datePtr = new Date; // 动态分配内存空间
    datePtr->year = 2023; // 使用箭头运算符指向成员变量
    datePtr->month = 9;
    datePtr->day = 11;
    delete datePtr; // 释放内存空间
    return 0;
}