C++之变量与常量

#include <iostream>
 
using namespace std;
//宏常量
#define day 7
 
int main() {
    std::cout << "一周里共有" << day << "天" << std::endl;
    //const修饰的变量
    const int month = 12;
    cout << "一年有" << month << "个月份" << endl;
    //变量的定义
    //语法: 数据类型 变量名 = 初始值
    int _aa = 10;
    int aa_ = 10;
    int _aa123 = 10;
    int num = 20;
    int Num = 20;
    cout << _aa << endl;
    cout << aa_ << endl;
    cout << _aa123 << endl;
    cout << num << endl;
    cout << Num << endl;
 
    return 0;
}