Home  >  Article  >  Backend Development  >  What is the use of "is" keyword in C#?

What is the use of "is" keyword in C#?

WBOY
WBOYforward
2023-09-04 19:09:03800browse

C# 中“is”关键字有什么用?

#"is" keyword is used to check whether an object can be converted to a specific type. The return type of the operation is Boolean.

Example

using System;
namespace DemoApplication{
   class Program{
      static void Main(){
         Employee emp = new PermanentEmployee{
            ID = 1,
            Name = "Martin"
         };
         // Returns true as the derived type can be converted to base type.
         if (emp is Employee){
            Console.WriteLine(emp.Name + " is Employee");
         }
         else{
            Console.WriteLine(emp.Name + " is not Employee");
         }
         //Returns true, as the actual object is of type PermanentEmployee.
         if (emp is PermanentEmployee){
            Console.WriteLine(emp.Name + " is PermanentEmployee");
         }
         else{
            Console.WriteLine(emp.Name + " is not PermanentEmployee");
         }
         //Returns false, as PermanentEmployee object cannot be converted to
         //ContractEmployee.
         if (emp is ContractEmployee){
            Console.WriteLine(emp.Name + " is ContractEmployee");
         }
         else{
            Console.WriteLine(emp.Name + " is not ContractEmployee");
         }
      }
   }
   class Employee{
      public int ID { get; set; }
      public string Name { get; set; }
   }
   class PermanentEmployee : Employee{
      public int AnnualSalary { get; set; }
   }
   class ContractEmployee : Employee{
      public int HourlySalary { get; set; }
   }
}

The above is the detailed content of What is the use of "is" keyword in C#?. For more information, please follow other related articles on the PHP Chinese website!

Statement:
This article is reproduced at:tutorialspoint.com. If there is any infringement, please contact admin@php.cn delete
Previous article:What is C# programming?Next article:What is C# programming?