5.4.4 排序

string names = {
               "Christina Aguillera",
               "Shakira",
               "Beyonce",
               "Gwen Stefani"
             };

Array.Sort(names);

foreach (string name in names)
{
   Console.WriteLine(name);
}

public class Person : IComparable
{
  public int CompareTo(object obj)
  {
    Person other = obj as Person;
    return this.lastname. CompareTo(other.lastname);
}
//…

Person[] persons = {
     new Person("Emerson", "Fittipaldi"),
     new Person("Niki", "Lauda"),
     new Person("Ayrton", "Senna"),
     new Person("Michael", "Schumacher"),
};

Array.Sotr(persons);
foreach (Person p in persons)
{
  Console.WriteLine(p);
}

public class PersonComparer : IComparer
{
  public enum PersonCompareType
  { 
    Firname,
Lastname
}

  private PersonCompareType compareType;

  public PersonComparer(PersonCompareType compareType)
  {
     this. compareType = compareType;
}

public int Compare(object x, object y)
{
       Person p1 = x as Person;
       Person p1 = y as Person;
       Switch (compareType)
       {
           case PersonCompareType.Firstname:
              return p1. Firstname. CompareTo(p2. Firstname);
           case PersonCompareType.Lastname:
              return p1. Lastname. CompareTo(p2. Lastname);
           default:
              throw new ArgumentException("unexpexted compare type")
}
}
}

Array.Sort(persons,
new PersonComparer(PersonComparer. PersonCompareType.Firstname));
foreach (Person p in persons)
{
  Console.WriteLine(p);
}