C#基础

// See https://aka.ms/new-console-template for more information
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace demo1
{
    class Program
    {
        static void Main(string[] args)
        {
            //int n = 100;
            //double f = 3.14; 
            //decimal mymoney = 5000m;
            //Console.WriteLine(n);
            //Console.WriteLine(f);
            //Console.WriteLine(mymoney);
            //Console.WriteLine("d");
            //Console.WriteLine('a');
            //Console.ReadKey();
            //int n1 = 50;
            //int n2 = 20;
            //n1 = n1 - n2;  
            //n2 = n1 + n2;   //  n2 = n1 - n2 + n2; 
            //n1 = n2 - n1;   //  n1 = n1 - n2 + n2 - n1 + n2;
            //Console.WriteLine("交换后，n1={0},n2={0}", n1, n2);
            //Console.ReadKey();

            //Console.WriteLine("请输入你的姓名：");
            //string name=Console.ReadLine();
            //Console.WriteLine("你的姓名是：{0}", name);
            //Console.ReadKey();
            //Console.WriteLine("你喜欢吃什么水果：");
            //string fruit = Console.ReadLine();
            //Console.WriteLine("我也喜欢吃：{0}",fruit);
            //Console.ReadKey();

            //Console.WriteLine("你的姓名是：");
            //string name = Console.ReadLine();
            //Console.WriteLine("你的性别是：");
            //string sex = Console.ReadLine();
            //Console.WriteLine("你的年龄是：");
            //string age = Console.ReadLine();
            //Console.WriteLine("{0},你好,年龄是{1},是一个{2}生，", name, age, sex);
            //Console.ReadKey();

            //Console.WriteLine("你的年龄是：");
            //string age = Console.ReadLine();//有这么一句，上面的打印输入才有效，底下要有接收的
            //Console.ReadKey();

            //转义字符,最终只是一个字符
            //Console.WriteLine("今天是周一\n我需要上班");  //\n是换行
            //Console.WriteLine("我想要输出一\"\"个英文的引号");//  \"是一个英文的双引号
            //\t表示一个tab键
            //Console.WriteLine("人不\b楣，一樽还酹江月");//\b删掉前一个字符
            ////char c = '\b';
            //string path = @"F:\music\ds\d\xiaozenaliya.jpg";
            //Console.WriteLine(path);

            //            Console.WriteLine(@"谁怕，
            //一蓑烟雨任平生");
            //            Console.ReadKey();

            //算数运算符
            //计算成绩的总分和平均值
            //int chinese = 90;
            //int math = 67;
            //int english = 34;
            //Console.WriteLine("总成绩是{0},平均成绩是{1}", chinese + math + english, (chinese + math + english) / 3);

            //double pi = 3.14;
            //int r = 5;
            //double area = pi * r * r;
            //double perimeter = 2 * pi * r;
            //Console.WriteLine(area);
            //Console.WriteLine(perimeter);
            //等号两边的数据类型应当保持一致，如果不一致，发生以下条件将发生自动类型转换
            //int和double兼容（都是数据类型）
            //目标类型大于源类型
            //int number = 10;
            //double a = number;

            //int T_shirt = 35;
            //int trousers = 113;
            //int totalMoney = 3 * T_shirt + 2 * trousers;
            //Console.WriteLine(totalMoney);
            //double realMoney = totalMoney * 0.88;
            //Console.WriteLine(realMoney);
            //Console.WriteLine(a);
            //Console.ReadKey();

            double a = 101.11;
            int b = (int)a;

            double c = 10;
            int d = 3;
            double e = c / d;
            Console.WriteLine("{0:0.00}", e);//小数点后保留两位
            Console.WriteLine(b);
            Console.ReadKey();
        }
    }
}

//#region  
//Console.ReadKey();
//#endregion

//Console.WriteLine("Hello, World!");
//Console.ReadKey();//暂停当前程序，等待用户按下任意键继续，按下的任意键将显示在控制台当中
//Console.WriteLine("我也是 hello world");
//Console.ReadKey();
//int number;