c#基础

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

namespace c练习
{
    class Program
    {
        static void Main(string[] args)
        {
            /* string[] str = { "aaa", "ddd", "bbb","ccc" };
             Array.Sort(str);//字符串数组排序a~z;
             for (int i = 0; i < str.Length; i++)
             {
                 if (i != str.Length - 1)
                     Console.Write(str[i] + ",");
                 else
                     Console.Write(str[i]);
             }
             Console.ReadKey();*/


            /*string str1 = "deasfgders";
            string substr="sf";
            int count=0;
            if (str1.IndexOf(substr) < 0)//字符串中是否包含子字符串
                Console.WriteLine(str1 + "不包含" + substr);
            else
            {
                while (str1.IndexOf(substr) >= 0)
                {
                    str1=str1.Substring(str1.IndexOf(substr) + substr.Length);//字符串出现的次数
                    count++;
                }
                Console.WriteLine("{0}出现了{1}次",substr,count);
            }
            Console.ReadKey();*/


            /*string str2 = "hello,new world";
            string[] substr = str2.Split(',',' ');//返回指定字符串分割的字符串数组
            foreach (string substr1 in substr)
                Console.WriteLine(substr1);
            Console.ReadKey();*/


            /*string[] str = { "aaa", "ddd", "bbb", "ccc" };
            string  newstr =string.Join("@",str);//字符串的连接
            Console.WriteLine(newstr);
            Console.ReadKey();*/


            /*int[] integer = {2,3,5,7,9,11};
            int max = integer.Max();
            int min = integer.Min();
            double average = integer.Average();
            int sum = integer.Sum();
            Console.WriteLine("最大值是"+max);//求数组最大值
            Console.WriteLine("最小值是" + min);//求数组最大值
            Console.WriteLine("平均值值是" + average);//求数组最大值
            Console.WriteLine("数组的和是" + sum);//求数组的和
            Console.ReadKey();*/


            /*int[] integer = { 2, 3, 1, 4, 5, 6, 5, 7 };
            for(int i=0;i<integer.Length-1;i++)//选择排序
                for (int j = i + 1; j < integer.Length; j++)
                    if (integer[i] > integer[j])
                    {
                        int temp = integer[i];
                        integer[i] = integer[j];
                        integer[j] = temp;
                    }
            for (int i = 0; i < integer.Length; i++)
                Console.Write(integer[i]+" ");
            Console.WriteLine();

           
            for(int i=0;i<integer.Length-1;i++)//冒泡排序
                for(int j=0;j<integer.Length-1-i;j++)
                    if (integer[j] > integer[j + 1])
                    {
                        int temp = integer[j];
                        integer[j] = integer[j + 1];
                        integer[j + 1] = temp;
                    }
            for (int i = 0; i < integer.Length; i++)
                Console.Write(integer[i] + " ");
            Console.ReadKey();*/


            /*int[] integer=new int[4];//数组的大小是固定的，数据类型一定
            ArrayList arr = new ArrayList();//集合的大小可变，可以存放各种类型的数据
            arr.Add("abc");
            arr.Add("def");
            arr.Add("bcd");
            arr.Reverse();
            foreach (object arrs in arr)
            {
                Console.WriteLine(arrs);
            }
            arr.Sort();
            foreach (object arrs in arr)
            {
                Console.WriteLine(arrs);
            }
            Console.ReadKey();*/

            Console.WriteLine(Convert.ToString(88, 2));//十进制转换为二进制
            Console.WriteLine(Convert.ToString(88, 8));//十进制转换为八进制
            Console.WriteLine(Convert.ToString(88, 16));//十进制转换为十六进制

            Console.WriteLine(Convert.ToInt32("1001011", 2));//二进制转换为十进制
            Console.WriteLine(Convert.ToInt32("77", 8));//八进制转换为十进制
            Console.WriteLine(Convert.ToInt32("aa", 16));//八进制转换为十进制
            Console.ReadKey();

        }


    }
}

 

            //string s1 = "qqq,ggg,ggg,ddd|ccc.eee";//字符串的拆分
            //string[] str = s1.Split(',','|','.');
            //foreach (string item in str)
            //Console.WriteLine(item);

            //string s1 = "sds,,sdsd,d,e";
            //string[] strs = s1.Split(new char[]{','},StringSplitOptions.
            //    RemoveEmptyEntries);//除去空格
            //foreach (string item in strs)
            //    Console.WriteLine(item);

            string ss = "http:\\www.baidu.com";//第一个左斜线是转移字符
            string yuming = ss.Substring(6);//输出为www.baidu.com
            Console.WriteLine(yuming);
            Console.ReadKey();

 

            //字符串倒序
           /* string s = Console.ReadLine();
            char temp;
            for (int i = s.Length - 1; i >= 0;i--)
            {
                Console.Write(s[i]);
            }*/
           
            //单词倒序
            /*string s = Console.ReadLine();
            string[] str = s.Split(' ');
            for (int i = str.Length - 1; i >= 0; i--)
            {
                Console.Write(str[i]+" ");
            }*/
            //显示用户名和域名 
            /*string email = Console.ReadLine();
            int index = email.IndexOf('@');
            string name = email.Substring(0, index);
            Console.WriteLine(name);
            string yuming = email.Substring(index+1);
            Console.WriteLine(yuming);*/

            Console.ReadKey();