C # Programming Guide (4) Tuple)

Group Meta is a new feature introduced by C #4.0. It must be Based on. NET Framework 4.0 or later. Group elements use generics to simplify the definition of a class.

 

The following code is used as an example:

 

 

  1     public class Point
 2     {
 3         public int X { get; set; }
 4         public int Y { get; set; }
 5     }
 6 
 7 
 8             //the user customer data type.
 9              Point p = new Point() { X = 10, Y = 20 };
10             //use the predefine generic tuple type.
11              Tuple<int, int> p2 = new Tuple<int, int>(10, 20);
12             
13             //
14              Console.WriteLine(p.X + p.Y);
15             Console.WriteLine(p2.Item1 + p2.Item2);

 

 

A simple class that contains two Int type members. The traditional method definition point requires a lot of code, but there is only one sentence to use tuple. The group elements are mostly used for the return value of the method. If a function returns multiple types, you can define a tuple type instead of using output parameters such as out and ref. Very convenient.

 

The following columns are slightly more complex:

 

  1             //1 member
 2              Tuple<int> test = new Tuple<int>(1);
 3             //2 member ( 1< n <8 )
 4              Tuple<int, int> test2 = Tuple.Create<int, int>(1,2);
 5             //8 member , the last member must be tuple type.
 6              Tuple<int, int, int, int, int, int, int, Tuple<int>> test3 = new Tuple<int, int, int, int, int, int, int, Tuple<int>>(1, 2, 3, 4, 5, 6, 7, new Tuple<int>(8));
 7 
 8             //
 9              Console.WriteLine(test.Item1);
10             Console.WriteLine(test2.Item1 + test2.Item2);
11             Console.WriteLine(test3.Item1 + test3.Item2 + test3.Item3 + test3.Item4 + test3.Item5 + test3.Item6 + test3.Item7 + test3.Rest.Item1);

 

The first definition contains a member.

The second definition contains two members and is initialized using the create method.

The third definition shows that tuple supports a maximum of 8 members. If there are more than 8 members, nesting is required. Note that 8th members are special. If there are 8 members, 8th must be nested to define tuple. As shown above.

 

 

Here are two examples of nested definitions:

 

 1             //2 member ,the second type is the nest type tuple.
2              Tuple<int, Tuple<int>> test4 = new Tuple<int, Tuple<int>>(1, new Tuple<int>(2));
3             //10 member datatype. nest the 8 parameter type.
4              Tuple<int, int, int, int, int, int, int, Tuple<int, int, int>> test5 = new Tuple<int, int, int, int, int, int, int, Tuple<int, int, int>>(1, 2, 3, 4, 5, 6, 7, new Tuple<int, int, int>(8, 9, 10));
5  
6 
7             //
8              Console.WriteLine(test4.Item1 + test4.Item2.Item1);
9             Console.WriteLine(test5.Item1 + test5.Item2 + test5.Item3 + test5.Item4 + test5.Item5 + test5.Item6 + test5.Item7 + test5.Rest.Item1 + test5.Rest.Item2 + test5.Rest.Item3);

 

 

 

Sample Code: Download