【C#视频】——基础知识点（2）

反转

1.             string[] text = {"我","是","好人"};                          for (int i = text.Length-1; i >= 0; i--)             {                 Console.Write(text[i] + "\t");             } 2.             string[] text = {"我","是","好人"};             Array.Reverse(text);             for (int i = 0; i < text.Length; i++)             {                 Console.Write(text[i] + "\t");             } 3. string[] text = {"我","是","好人"};             string temp = "";             for (int i = 0; i < text.Length/2; i++)             {                 temp = text[i];                 text[i] = text[text.Length - 1 - i];                 text[text.Length - 1 - i] = temp;                              }             for (int i = 0; i < text.Length; i++)             {                 Console.Write(text[i] + "\t");             }             Console.ReadKey();

移除

            string str = "熊 祁 很   纯洁，而     且还很  ----帅";             char []chs=new char[]{' ','-'};             string []result=str.Split (chs, StringSplitOptions .RemoveEmptyEntries );//把不想要的切除             for (int i = 0; i < result.Length ; i++)             {                 Console.Write(result[i]);             }                   Console.ReadKey(); Split (chs, StringSplitOptions .RemoveEmptyEntries );//把不想要的切除             for (int i = 0; i < result.Length ; i++)             {                 Console.Write(result[i]);             }                   Console.ReadKey();             string date = "2018--------5-----22";             char []chs=new char[]{'-'};                         string []time=date.Split (chs, StringSplitOptions .RemoveEmptyEntries );//把不想要的切除                        Console.Write("{0}年{1}月{1}日",time[0],time[1],time[2]);                              Console.ReadKey();Split (chs, StringSplitOptions .RemoveEmptyEntries );//把不想要的切除                        Console.Write("{0}年{1}月{1}日",time[0],time[1],time[2]);                              Console.ReadKey();             string email = "abc@163.com";             string []strs=email.Split ('@');             Console.WriteLine ("用户名是{0}",strs[0]);             Console.WriteLine ("域名是{0}",strs[1]); Split ('@');             Console.WriteLine ("用户名是{0}",strs[0]);             Console.WriteLine ("域名是{0}",strs[1]);

        static void Main(string[] args)         {             string text = "老苏果然很邪恶";             text = text.Remove(5);             Console.WriteLine(text);             Console.ReadKey();         } Remove(5);             Console.WriteLine(text);             Console.ReadKey();         }

            string text = "老苏果然很邪恶";             text = text.Remove(2,3);//从哪个地方开始移除，移除多少个             Console.WriteLine(text);             Console.ReadKey();

 

替换

 

            string name = "小羊很邪恶";             name = name.Replace('很', '不');             char[] chs = new char[] { '-' };                Console.Write(name);             Console.ReadKey();Replace('很', '不');             char[] chs = new char[] { '-' };                Console.Write(name);             Console.ReadKey();

截取

            string name = "哈哈，小羊很邪恶";             name = name.Substring(4);//截取字符串             Console.Write(name);             Console.ReadKey();Substring(4);//截取字符串             Console.Write(name);             Console.ReadKey();

显示：羊很邪恶

            string name = "哈哈，小羊很邪恶";             name = name.Substring(4,2);//截取字符串             Console.Write(name);             Console.ReadKey();Substring(4,2);//截取字符串             Console.Write(name);             Console.ReadKey();

显示：羊很

判断开头和结尾

            string str = "小羊很纯洁";             bool result = str.StartsWith("小羊很");//判断字符串是否以某个字符串开头             //bool result = str.EndsWith ("纯洁");//判断字符串是否以某个字符串结尾             //str.Contains("小");//判断字符串中有没有的             if (result)             {                 Console.WriteLine("有这个字符串");             }             else             {                 Console.WriteLine("没有这个字符串");             }             Console.ReadKey(); StartsWith("小羊很");//判断字符串是否以某个字符串开头             //bool result = str.EndsWith ("纯洁");//判断字符串是否以某个字符串结尾             //str.Contains("小");//判断字符串中有没有的             if (result)             {                 Console.WriteLine("有这个字符串");             }             else             {                 Console.WriteLine("没有这个字符串");             }             Console.ReadKey();             string str = "小羊很纯洁，哈哈哈";             int index = str.IndexOf("纯");//如果这个字符串在这个字符串中，那么就会把这个字符串的索引显示出来，如果找不到这个字符串，返回的结果是-1                 int index = str.IndexOf("哈", 8);//找一个字符串从某个索引开始找，找到了就返回索引，找不到就返回-1             int index =str.LastIndexOf ("哈");//找最后一个字符串的索引，三个哈中最后一个哈             Console.WriteLine(index);             string path = @"E:\Program Files\Microsoft Visual Studio 10.0\VC#\Snippets\2052\Visual C#\小杨.exe";             int index = path.LastIndexOf("\\");             string st = path.Substring(index + 1);             Console.WriteLine(st);             Console.ReadKey();IndexOf("纯");//如果这个字符串在这个字符串中，那么就会把这个字符串的索引显示出来，如果找不到这个字符串，返回的结果是-1                 int index = str.IndexOf("哈", 8);//找一个字符串从某个索引开始找，找到了就返回索引，找不到就返回-1             int index =str.LastIndexOf ("哈");//找最后一个字符串的索引，三个哈中最后一个哈             Console.WriteLine(index);             string path = @"E:\Program Files\Microsoft Visual Studio 10.0\VC#\Snippets\2052\Visual C#\小杨.exe";             int index = path.LastIndexOf("\\");             string st = path.Substring(index + 1);             Console.WriteLine(st);             Console.ReadKey();

插入

            string str = "小羊很纯洁，哈哈哈";             str = str.Insert(9, "!");//在某个索引处查入字符串                        Console.WriteLine(str);             Console.ReadKey(); Insert(9, "!");//在某个索引处查入字符串                        Console.WriteLine(str);             Console.ReadKey();             string[] names = {"卡卡西","熊祁","白起","我爱罗","赤井秀一","服部平次" };             string st = string.Join("|", names);             Console.WriteLine(st);             Console.ReadKey(); Join("|", names);             Console.WriteLine(st);             Console.ReadKey();

            string str = "";             bool result= string.IsNullOrEmpty("哈哈");             if (result)             {                 Console.WriteLine("有东西");              }             else             {                 Console.WriteLine("你猜");             }             Console.ReadKey();IsNullOrEmpty("哈哈");             if (result)             {                 Console.WriteLine("有东西");              }             else             {                 Console.WriteLine("你猜");             }             Console.ReadKey();

忽略大小写

            Console.WriteLine("输入第一门课程");             string str1 = Console.ReadLine();             Console.WriteLine("输入第二门课程");             string str2 = Console.ReadLine();             bool result = str1.Equals(str2, StringComparison.OrdinalIgnoreCase);//忽略大小写比较              if (result)             {                 Console.WriteLine("课程一样");             }             else             {                 Console.WriteLine("课程不同");             }                       Console.ReadKey();Equals(str2, StringComparison.OrdinalIgnoreCase);//忽略大小写比较              if (result)             {                 Console.WriteLine("课程一样");             }             else             {                 Console.WriteLine("课程不同");             }                       Console.ReadKey();

读文件

using System.IO;         static void Main(string[] args)         {             //找到文本文件             string path=@"C:\Documents and Settings\Administrator\桌面\book.txt";             //读取文本文件，是一行一行的读             string []text= File.ReadAllLines (path,Encoding.Default);             for (int i = 0; i < text.Length ; i++) {     string []sts= text [i].Split (new char[]{' '},StringSplitOptions .RemoveEmptyEntries );                                if (sts[0].Length >=10)             {             Console.WriteLine( sts[0].Substring (0,8)+"...|"+sts[1]);             }                 else             {                     Console.WriteLine (sts[0]+"|"+sts[1]);             } }                         Console.ReadKey();         }