IComparable

Question

This program is given in the following website (http://www.dotnetperls.com/icomparable). Salary is sorted by

return other.Salary.CompareTo(this.Salary);. Problem is highlighted in the program.

If we interchange "this.Salary" and "other.Salary" that means

return this.Salary.CompareTo(other.Salary);

the output(Salary) is arranged as follows (Low to High). Please explain the reason.

8000,Lucy
10000,Andrew
10000,Janet
10000,Steve
500000,Bill

using System;
using System.Collections.Generic;

class Employee : IComparable<Employee>
{
public int Salary { get; set; }
public string Name { get; set; }

public int CompareTo(Employee other)
{
// Alphabetic sort if salary is equal. [A to Z]
if (this.Salary == other.Salary)
{
return this.Name.CompareTo(other.Name);
}
// Default to salary sort. [High to low]
return other.Salary.CompareTo(this.Salary);
}

public override string ToString()
{
// String representation.
return this.Salary.ToString() + "," + this.Name;
}
}

class Program
{
static void Main()
{
List<Employee> list = new List<Employee>();
list.Add(new Employee() { Name = "Steve", Salary = 10000 });
list.Add(new Employee() { Name = "Janet", Salary = 10000 });
list.Add(new Employee() { Name = "Andrew", Salary = 10000 });
list.Add(new Employee() { Name = "Bill", Salary = 500000 });
list.Add(new Employee() { Name = "Lucy", Salary = 8000 });

// Uses IComparable.CompareTo()
list.Sort();

// Uses Employee.ToString
foreach (var element in list)
{
Console.WriteLine(element);
}
Console.ReadKey();
}

}
/*
500000,Bill
10000,Andrew
10000,Janet
10000,Steve
8000,Lucy
*/