C#学习之路，学习笔记 2.1 整形、浮点型和decimal型变量

<span style="font-size:14px;">using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace _1HellowTomorrow{    class Program    {        static void Main(string[] args)        {            //变量定义            int a = 7;            int b = 2;            int sum, dif, pro, quo;            sum = a + b;            dif = a - b;            pro = a * b;            quo = a / b;                        //输出到屏幕            Console.WriteLine("{0} + {1} = {2}", a, b, sum); //占位符的使用            Console.WriteLine("{0} - {1} = {2}", a, b, dif);            Console.WriteLine("{0} * {1} = {2}", a, b, pro);            Console.WriteLine("{0} / {1} = {2}", a, b, quo);            Console.WriteLine("Hellow Tomorrow");            //转换成2、8、16进制显示            Console.WriteLine(Convert.ToString(89, 2));            Console.WriteLine(Convert.ToString(89, 8));            Console.WriteLine(Convert.ToString(89, 16));            Console.WriteLine(Convert.ToString(25, 2));            //实数常量默认情况下是双精度的，为了把实数常量赋给单精度变量，需要            //添加后缀f或F，将其标志为单精度实数，比如：12.34567f   3.1415926F            float x = 3.14159265358979f;            double x1 = 3.14159265358979f;            //float x2 = 3.14159265358979;    此写法报错            double y = 3.14159265358979;            Console.WriteLine("x = {0}", x);            Console.WriteLine("x1 = {0}", x1);            //Console.WriteLine("x2 = {0}", x2);            Console.WriteLine("y = {0}", y);            //小明有44444.14元钱，小娟有66666.51元钱，编写一个程序，计算他们两个共有多少钱            float balanceOfMing = 44444.14f;            float balanceOfJuan = 66666.51f;            float total = balanceOfMing + balanceOfJuan;            Console.WriteLine("小明：￥{0}", balanceOfMing);            Console.WriteLine("小娟：￥{0}", balanceOfJuan);            Console.WriteLine("合计：￥{0}", total);  //结果应为111110.65，实则为111110.6            /* 出现精度不足的现象，             *              * 由此引入decimal型（128位）             * 注意！由于实数常量默认情况下为double型数据，要将其值赋给decimal型变量             * 需要添加后缀m或M，将其标记为decimal型数字             */            //引入decimal后程序如下            decimal meonyOfMing = 44444.14m;            decimal meonyOfJuan = 66666.51m;            decimal sumOfThem = meonyOfJuan + meonyOfMing;            Console.WriteLine("小明：￥{0}", meonyOfMing);            Console.WriteLine("小娟：￥{0}", meonyOfJuan);            Console.WriteLine("合计：￥{0}", sumOfThem);  //正确        }    }}</span>

运行结果如下：

<img src="http://img.blog.csdn.net/20151001141603607?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast" alt="" />