//introduction of system fuction
using System;

//name space命名空间

//class
class MainClass
{
//main method
//A program starts with the main method and ends with the main method
//A program has only one main method

/// <summary>
/// The entry point of the program, where the program control starts and ends.
/// </summary>
/// <param name="args">The command-line arguments.</param>
public static void Main (string[] args)
{

    /*
         * 多行注释中可以包含回车
        */
    /*
    //All the programs written earlier must be written in the main method
    //在计算机中 最小存储单位 位 bit
    //在计算机中 最小的使用单位 字节 Byte
    //1字节 = 8位

    //变量 就是一块内存
    //创建变量： 从一整块内存中，获取一小块内存
    //定义变量
    //数据类型 变量名 = 值
    //整型
    //这里说的变量指的是 n1
    int n1 = 10;
    //如果想改变变量中的值
    n1 = 20;
    //系统提供的，作用将指定的数据输出到控制台
    Console.WriteLine (n1);

    //浮点型 单精度
    float f1 = 2.1234567f;
    Console.WriteLine (f1);

    //浮点型 双精度
    double f2 = 0.123456789123456789;
    Console.WriteLine (f2);

    //bool 布尔类型 true false
    bool b1 = true;
    bool b2 = false;

    //字符类型
    char c1 = 'a';
    Console.WriteLine (c1);

    //字符串 加双引号
    string c2 = "Hello World!";
    Console.WriteLine (c2);

    //命名规范
    //1.只能使用数字、字母、下划线、@组成，数字不能开头，@只能开头
    int @a_1 = 10;
    //2.不可以与系统保留字同名
    //3.不能使用重复的变量名
    int @A_1 = 10;
    //规范
    //4.见名知意
    int age = 18;
    //5.驼峰命名法
    string myNameIs = "Lee";

    //不要用
    string 你好 = "Hello";
    Console.WriteLine (你好);

    int a1 = 1;
    int a2 = 1;
    int a3 = 1;
    int a4 = 1;
    int a5 = 1;
    int a6 = 1;
    int a7 = 1;
    int a8 = 1;
    int a9 = 1;
    int b11 = 1;
    int b22 = 1;
    int b3 = 1;
    int b4 = 1;
    int b5 = 1;
    int b6 = 1;
    int b7 = 1;
    int b8 = 1;
    int b9 = 1;

    bool c = true;
    bool c21 = true;
    bool c3 = true;
    bool c4 = true;
    bool c5 = true;
    bool c6 = true;
    bool c7 = true;
    bool c8 = true;
    bool c9 = true;
    bool d1 = false;
    bool d2 = false;
    bool d3 = false;
    bool d4 = false;
    bool d5 = false;
    bool d6 = false;
    bool d7 = false;
    bool d8 = false;
    bool d9 = false;

    char f = 'a';
    char f12 = 'a';
    char f22 = 'a';
    char f3 = 'a';
    char f4 = 'a';
    char f5 = 'a';
    char f6 = 'a';
    char f7 = 'a';
    char f8 = 'a';
    char f9 = 'a';
    char g1 = 'a';
    char g2 = 'a';
    char g3 = 'a';
    char g4 = 'a';
    char g5 = 'a';
    char g6 = 'a';
    char g7 = 'a';
    char g8 = 'a';
    char g9 = 'a';

    string h1 = "kk";
    string h2 = "kk";
    string h3 = "kk";
    string h4 = "kk";
    string h5 = "kk";
    string h6 = "kk";
    string h7 = "kk";
    string h8 = "kk";
    string h9 = "kk";
    string u1 = "kk";
    string u2 = "kk";
    string u3 = "kk";
    string u4 = "kk";
    string u5 = "kk";
    string u6 = "kk";
    string u7 = "kk";
    string u8 = "kk";
    string u9 = "kk";

    float i1 = 2.5f;
    float i2 = 2.2f;
    float i3 = 2.5f;
    float i4 = 2.8f;
    float i5 = 2.8f;
    float i6 = 2.9f;
    float i7 = 2.8f;
    float i8 = 2.8f;
    float i9 = 2.9f;
    float o1 = 2.8f;
    float o2 = 2.8f;
    float o3 = 2.8f;
    float o4 = 2.8f;
    float o5 = 2.8f;
    float o6 = 2.7f;
    float o7 = 2.7f;
    float o8 = 2.8f;
    float o9 = 2.7f;

    double t1 = 2.44;
    double t2 = 2.55;
    double t3 = 2.8787;
    double t4 = 2.578;
    double t5 = 2152.55;
    double t6 = 2.44;
    double t7 = 2.77;
    double t8 = 2.77;
    double t9 = 2.7474;
    double r1 = 2.55;
    double r2 = 2.44;
    double r3 = 2.447;
    double r4 = 2.77;
    double r5 = 2.44;
    double r6 = 2.44;
    double r7 = 2.44;
    double r8 = 32.44;
    double r9 = 2.44;

    */

    //      string str3 = "1";
    //      bool strBool = bool.Parse (str3);
    //      Console.WriteLine (strBool);
    //
    //


}

}