c#day01

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace testmysql
{
    class Lianxi
    {
        //变量交换
        const float PI = 3.14f;
        public void xiti1(int i ,int j){

            Console.WriteLine("交换前：i="+i+" j="+j);
            int k;
            k = i;
            i = j;
            j = k;
            Console.WriteLine("交换后：i=" + i + " j=" + j);
        }
        //总分  平均分
        public void xiti2(float csharp ,float unity, float math)
        {
            float score;
            float average;

            score = csharp + unity + math;
            average = score / ;
            Console.WriteLine("总分为： "+score);
            Console.WriteLine("平均分为； "+average);

        }
        //圆的面积周长
        public void xiti3(float r)
        {
            float area;
            float perimeter;

            area = PI * r * r;
            perimeter =  * PI * r;

            Console.WriteLine("圆的面积："+area);
            Console.WriteLine("圆的周长："+perimeter);

        }

        public void xiti4(float tshirt ,int tshirt_univalent,float pants, int pants_univalent )
        {
            float total;
            float discount;

            total = tshirt *(float) tshirt_univalent;

            discount = total * 0.38f;

            Console.WriteLine("一共要付:{0}元",total);
            Console.WriteLine("打折后的价格为：{0}元",discount);
        }
    }

    /* class Maintests
    {
       static void Main(string[] args)
        {
            Lianxi liaxi = new Lianxi();
            liaxi.xiti1(20,10);
            liaxi.xiti2(80,90,99);
            liaxi.xiti3(5);
            liaxi.xiti4(285,2,720,3);

        }
    }*/

}