C#基础知识

 

 

1. 输出

Console.WriteLine("123");

 

 

字符串 String

 

1. 字符串插入变量

   string aFriend = "Scott";
   Console.WriteLine($"Hello{aFriend}");

    

2. 变量的长度

   Console.WriteLine($"Hello{aFriend.Length}");

    

3. 字符串的空白

   string greeting = "        Hello World     " ;
   
   string trimmedGreeting=greeting.TrimStart();
   
   trimmedGreeting=greeting.TrimEnd();
   
   trimmedGreeting=greeting.Trim();

    

4. 字符串替换

   string sayHello = "Hekki World";
   Console.WriteLine(sayHello);
   
   sayHello=sayHello.Replace("Hello","Greetings");
   Console.WriteLine(sayHello);

    

5. 字符串字母变大变小

   string sayHello = "Hekki World";
   Console.WriteLine(sayHello.ToUpper());
   Console.WriteLine(sayHello.ToLower());

    

6. 字符串是否包含这些字符

   string songLyrics = "You say goodbye,and I say hello";
   
   Console.WriteLine(songLyrics.Contains("goodbye"));
   Console.WriteLine(songLyrics.Contains("greetings"));

   输出true或false

 

 

 

Number

1. 加减乘除

   int a=18;
   int b=6;
   int c=a+b;
   Console.WriteLine(c);
   
   
   
   int a=18;
   int b=6;
   int c=a*b;
   Console.WriteLine(c);
   
   
   int a=18;
   int b=6;
   int c=a/b;
   Console.WriteLine(c);
   
   
   int a=18;
   int b=6;
   int c=2;
   int d=(a+b)*c;
   Console.WriteLine(d);
   
   
   ................

    

2. Integer 的精准最大和最小

   int max=int.MaxValue;
   int min=int.MinValue;

   double max=double .MaxValue;
   double min=double .MinValue;

    

3. 小数  decimals

   double a=1.0;
   double b=3.0;
   Console.WriteLine(a / b);
   
   decimal c=1.0M;
   decimal d=3.0M;
   Console.WriteLine(c/d);
   
   long min=long.MinValue;
   long max=long.MaxValue;
   
   short min1=short .MinValue;
   short max1=short .MaxValue;

    

 

 

判断 循环

if

 while 

do while 

for

foreach

 

 

Arrays, List, and Collections

https://blog.csdn.net/qq_44034384/article/details/106342294

var names = new List<string>{"<name>"};

 

 

 

Sort, Search, and Index Lists 

数组的   Sort();       IndexOf();

 

 

 

 

 

Lists of Other Types