C# Program to Implement IComparable Interface

// C# program to demonstrate how to
// implement IComparable interface 
using System;
using System.Collections.Generic;

class GFG{

// Driver code
static public void Main()
{
    
    // Create an array of employees 
    // using collection initializer
    Employee[] employees = new Employee[]
    {
        new Employee(1, "Susmita"),
        new Employee(5, "Soniya"),
        new Employee(3, "Rohit"),
        new Employee(2, "Mohit"),
        new Employee(4, "Pihu")
    };
    
    // Displaying the employee's array before sorting
    Console.WriteLine("Before sorting employees array");
    foreach(var emp in employees)
    {
          Console.WriteLine("ID - {0}, Employee Name - {1}", 
                            emp.ID, emp.EmployeeName);
    }
    
    // Sorts the employees array in ascending 
    // order on basis of id of the employee
    Array.Sort(employees);   
      
    Console.WriteLine();
      
    // Printing the employee's array after sorting
    Console.WriteLine("After sorting employees array");
    foreach(var emp in employees)
    {
          Console.WriteLine("ID - {0}, Employee Name - {1}",  
                            emp.ID, emp.EmployeeName);
    }
}
}

// Implementing IComparable interface
public class Employee : IComparable{
    
public int ID;
public string EmployeeName;

// Employee constructor
public Employee(int id, string employeename)
{
    this.ID = id;
    this.EmployeeName = employeename;
}

// Implementation of the CompareTo() method which takes
// an object as an input and return integer value depending on
// the comparison between current object and incoming object,
public int CompareTo(object incomingobject)
{
    
      // Storing incoming object in temp variable of 
      // current class type
      Employee incomingemployee = incomingobject as Employee;
  
      return this.ID.CompareTo(incomingemployee.ID);
}
}