Mega Code Archive
Provide different IComparer for a Class
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using System;
using System.Collections.Generic;
public class Employee : IComparable<Employee>
{
private string name;
private int level;
private class AscendingLevelComparer : IComparer<Employee>
{
public int Compare(Employee x, Employee y)
{
if (x == null && y == null)
return 0;
else if (x == null)
return -1;
else if (y == null)
return 1;
if (x == y)
return 0;
return x.level - y.level;
}
}
public Employee(string name, int level)
{
this.name = name;
this.level = level;
}
public static IComparer<Employee> LevelSorter
{
get { return new AscendingLevelComparer(); }
}
public override string ToString()
{
return string.Format("{0}: Level = {1}", name, level);
}
public int CompareTo(Employee other)
{
if (other == null)
return 1;
if (other == this)
return 0;
return string.Compare(this.name, other.name, true);
}
}
public class MainClass
{
public static void Main()
{
List<Employee> employeeList = new List<Employee>();
employeeList.Add(new Employee("A", 1));
employeeList.Add(new Employee("B", 5));
employeeList.Add(new Employee("C", 2));
employeeList.Add(new Employee("D", 8));
employeeList.Add(new Employee("E", 5));
Console.WriteLine("Unsorted employee list:");
foreach (Employee n in employeeList)
{
Console.WriteLine(" " + n);
}
Console.WriteLine(Environment.NewLine);
Console.WriteLine("Employee list sorted by name (default order):");
employeeList.Sort();
foreach (Employee n in employeeList)
{
Console.WriteLine(" " + n);
}
Console.WriteLine(Environment.NewLine);
Console.WriteLine("Employee list sorted by level:");
employeeList.Sort(Employee.LevelSorter);
foreach (Employee n in employeeList)
{
Console.WriteLine(" " + n);
}
}
}
Unsorted employee list:
A: Level = 1
B: Level = 5
C: Level = 2
D: Level = 8
E: Level = 5
Employee list sorted by name (default order):
A: Level = 1
B: Level = 5
C: Level = 2
D: Level = 8
E: Level = 5
Employee list sorted by level:
A: Level = 1
C: Level = 2
E: Level = 5
B: Level = 5
D: Level = 8
]]>