class Person:IComparer<Person>
    {
        int age;
        public Person(int age)
        {
             this.age = age;
        }
        public int Age
        {
            get { return age; }
        }

        public int CompareTo(Person p)
        {
            return 1;
        }


    }

ArrayList al = new ArrayList();
al.Add(new Person(9));
al.Sort();

it throws an error: failed to compare 2 elements in array

Thanks

Edited 3 Years Ago by Dani: Formatting fixed

Because you didn't implement all interface methods!!

Error:
'fileStream.Person' does not implement interface member 'System.Collections.Generic.IComparer<fileStream.Person>.Compare(fileStream.Person, fileStream.Person)'

IComparer has Compare as method and not CompareTo

try this I find it in the MSDN on line

public class Person : System.IComparable<Person>
{
    string name;
    int age;

    public Person(string s, int i)
    {
        name = s;
        age = i;
    }

    // This will cause list elements to be sorted on age values.
    public int CompareTo(Person p)
    {
        return age - p.age;
    }

    public override string ToString()
    {
        return name + ":" + age;
    }

    // Must implement Equals.
    public bool Equals(Person p)
    {
        return (this.age == p.age);
    }
}

class Program
{
    static void Main()
    {
        //Declare and instantiate a new generic SortedList class.
        //Person is the type argument.
        SortedList<Person> list = new SortedList<Person>();

        //Create name and age values to initialize Person objects.
        string[] names = new string[] 
        { 
            "Franscoise", 
            "Bill", 
            "Li", 
            "Sandra", 
            "Gunnar", 
            "Alok", 
            "Hiroyuki", 
            "Maria", 
            "Alessandro", 
            "Raul" 
        };

        int[] ages = new int[] { 45, 19, 28, 23, 18, 9, 108, 72, 30, 35 };

        //Populate the list.
        for (int x = 0; x < 10; x++)
        {
            list.AddHead(new Person(names[x], ages[x]));
        }

        //Print out unsorted list.
        foreach (Person p in list)
        {
            System.Console.WriteLine(p.ToString());
        }
        System.Console.WriteLine("Done with unsorted list");

        //Sort the list.
        list.BubbleSort();

        //Print out sorted list.
        foreach (Person p in list)
        {
            System.Console.WriteLine(p.ToString());
        }
        System.Console.WriteLine("Done with sorted list");
    }
}

Edited 3 Years Ago by mike_2000_17: Fixed formatting

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