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Comment utiliser les indexeurs en C# 8.0 ?

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Libérer: 2023-09-12 18:53:03
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如何在C# 8.0中使用索引器?

^ opérateur - Il est connu comme l'opérateur d'indexation de la fin.

Il renvoie l'index relatif à la fin de la séquence ou de l'ensemble.

Par rapport à la méthode précédente, c'est la manière la plus concise et la plus simple de trouver le dernier élément.

METHODS.

company.listEmployees[^2].Name = "Nom de l'employé 2 modifié à l'aide d'une nouvelle syntaxe";

company.listEmployees[^5].Name = "Nom de l'employé 5 modifié à l'aide d'une nouvelle syntaxe";

entreprise. listEmployees[^8].Name = "Nom de l'employé 8 modifié à l'aide d'une nouvelle syntaxe";

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public class Employee{

   public int EmployeeId { get; set; }

   public string Name { get; set; }

   public string Gender { get; set; }

}

public class Company{

   public List<Employee> listEmployees;

   public Company(){

      listEmployees = new List<Employee>();

      listEmployees.Add(new Employee

      { EmployeeId = 1, Name = "SS", Gender = "Male" });

      listEmployees.Add(new Employee

      { EmployeeId = 2, Name = "SSS", Gender = "Female" });

      listEmployees.Add(new Employee

      { EmployeeId = 3, Name = "SSSS", Gender = "Male" });

      listEmployees.Add(new Employee

      { EmployeeId = 4, Name = "EE", Gender = "Female" });

      listEmployees.Add(new Employee

      { EmployeeId = 5, Name = "EEEE", Gender = "Female" });

      listEmployees.Add(new Employee

      { EmployeeId = 6, Name = "TTT", Gender = "Male" });

      listEmployees.Add(new Employee

      { EmployeeId = 7, Name = "FFF", Gender = "Male" });

      listEmployees.Add(new Employee

      { EmployeeId = 8, Name = "GGG", Gender = "Male" });

   }

   public string this[int employeeId]{

      get{

         return listEmployees.

         FirstOrDefault(x => x.EmployeeId == employeeId).Name;

      }

      set{

         listEmployees.

         FirstOrDefault(x => x.EmployeeId == employeeId).Name = value;

      }

   }

}

class Program{

   public static void Main(){

      Company company = new Company();

      Console.WriteLine("Name of Employee with Id = 2: " + company[2]);

      Console.WriteLine("Name of Employee with Id = 5: " + company[5]);

      Console.WriteLine("Name of Employee with Id = 8: " + company[8]);

      System.Console.WriteLine();

      Console.WriteLine("Changing names of employees with Id = 2,5,8");

      company[2] = "Employee 2 Name Changed";

      company[5] = "Employee 5 Name Changed";

      company[8] = "Employee 8 Name Changed";

      System.Console.WriteLine();

      Console.WriteLine("Name of Employee with Id = 2: " + company[2]);

      Console.WriteLine("Name of Employee with Id = 5: " + company[5]);

      Console.WriteLine("Name of Employee with Id = 8: " + company[8]);

      company.listEmployees[^2].Name = "Employee 2 Name Changed using new

      Syntax";

      company.listEmployees[^5].Name = "Employee 5 Name Changed using new

      Syntax";

      company.listEmployees[^8].Name = "Employee 8 Name Changed using new

      Syntax";

      System.Console.WriteLine();

      Console.WriteLine("Name of Employee with Id = 2: " +

      company.listEmployees[^2].Name);

      Console.WriteLine("Name of Employee with Id = 5: " +

      company.listEmployees[^5].Name);

      Console.WriteLine("Name of Employee with Id = 8: " +

      company.listEmployees[^8].Name);

      Console.ReadLine();

   }

}

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Name of Employee with Id = 2: SSS

Name of Employee with Id = 5: EEEE

Name of Employee with Id = 8: GGG

Changing names of employees with Id = 2,5,8

Name of Employee with Id = 2: Employee 2 Name Changed

Name of Employee with Id = 5: Employee 5 Name Changed

Name of Employee with Id = 8: Employee 8 Name Changed

Name of Employee with Id = 2: Employee 2 Name Changed using new Syntax

Name of Employee with Id = 5: Employee 5 Name Changed using new Syntax

Name of Employee with Id = 8: Employee 8 Name Changed using new Syntax

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source:tutorialspoint.com
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