A brief description of the role of C # generics

Generics: That is, a parameterized type is implemented to manipulate multiple data types on the same piece of code. Generic programming is a programming paradigm that abstracts types using "parameterized types" for more flexible reuse.

Overview of the role of C # generics

C # generics give code a stronger type-safe, better reuse, higher efficiency, and clearer constraints.

In a method, the value of a variable can be used as a parameter, but in fact the type of the variable can also be used as a parameter. Generics allow us to specify what this type parameter is when called. In. NET, the two obvious benefits that generics can bring to us are type safety and reduced boxing and unpacking.

In a method, the value of a variable can be used as a parameter, but in fact the type of the variable can also be used as a parameter. Generics allow us to specify what this type parameter is when called. In. NET, the two obvious benefits that generics can bring to us are: type safety and reduced boxing, unpacking.

Suppose we now have a people collection: Create a Person class

2. Public class person
4. {
6. Private string name;
8. Private int age;
12. Public Person (string Name, int age) //constructor
14. {
16. this. Age = age;
18. this. Name = name;
20. }
22. Public string Name
24. {
26. Set {This . Name = value;}
28. Get { return name;}
30. }
32. Public int age
34. {
36. Set {This . Age = value;}
38. Get { return age;}
40. }
42. }

We run the following at the entry point of the program to add an additional type of object to the collection, but when inserting the data there is no error and the compilation can pass, but "who is the King of Kung Fu?" "It's a problem when the field is converted to a person, which means that ArrayList is unsafe type.

2. Static void Main (string[] args)
4. {
6. ArrayList peoples = new ArrayList ();
8. Peoples.  ADD (new person ("dragon", 18));
10. Peoples.  ADD (new person ("Bruce Lee", 17));
12. Peoples. ADD ("Who is the King of Kung Fu?")  ");
14. foreach (person, in Peoples)
16. {
18. Console.WriteLine (person. Name + "This year" + person. Age + "old."  ");
20. }
22. }

So here we create a generic for a person, and when you want to insert another type into it, the compiler will give you an error.

2. Static void Main (string[] args)
4. {
6. list< person> peoples = new list< person> ();
8. Peoples.  ADD (new person ("dragon", 18));
10. Peoples.  ADD (new person ("Bruce Lee", 17));
12. Peoples. ADD ("Who is the King of Kung Fu?")  ");
14. foreach (person, in Peoples)
16. {
18. Console.WriteLine (person. Name + "This year" + person. Age + "old."  ");
20. }
22. }

The role of C # generics: Sorting

C # generics as a collection, sorting is indispensable. The sorting is based on the comparison with, to sort, first to compare. An object can have multiple comparison rules, but there can be only one default rule, and the default rule is placed in the class that defines the object. The default rule is defined in the CompareTo method, which belongs to the icomparable< t> generic interface.

2. Public class person:icomparable< person>
4. {
8. 。。。。。。
10. Public int CompareTo (person P) //Here adds a sort by age comparator
12. {
14. return This . Age-p.age;
16. }
18. }
22. Static void Main (string[] args)
24. {
26. list< person> peoples = new list< person> ();
28. Peoples.  ADD (new person ("NBS", 18));
30. Peoples.  ADD (new person ("Bruce Lee", 17));
32. Peoples.  ADD (new person ("House Little Dragon", 23));
34. Peoples.  ADD (new person ("Zhang Xiaolong", 42));
36. Peoples. Sort (); ///the sort () method without parameters to sort the collection
38. foreach (person, in Peoples)
40. {
42. Console.WriteLine (person. Name + "This year" + person. Age + "old."  ");
44. }
46. }

Well, here's a simple explanation of the role of C # generics.

A brief description of the role of C # generics