CODEWITHSUNDEEP
c#
ma7moud
ma7moud

Reputation: 423

get Idictionnary from Ilist

How to get a IDictionnay form a IList

Upvotes: 3

Views: 805

Answers (2)

Steve Willcock
Steve Willcock

Reputation: 26849

You can use Linq to easily get a Dictionary from a List by using the ToDictionary extension method and supplying an expression to get the key - e.g.

internal class Program
{
    private static void Main(string[] args)
    {
        IList<Person> list = new List<Person> {new Person("Bob", 40), new Person("Jill", 35)};
        IDictionary<string, Person> dictionary = list.ToDictionary(x => x.Name);
    }
}

public class Person
{
    private readonly int _age;
    private readonly string _name;

    public Person(string name, int age)
    {
        _name = name;
        _age = age;
    }

    public int Age
    {
        get { return _age; }
    }

    public string Name
    {
        get { return _name; }
    }
}

Alternatively, as Jon pointed out, if you need to use a different value for the Dictionary entries, you can also specify a second expression to get the value - as follows:

IDictionary<string, int> dictionary2 = list.ToDictionary(x => x.Name, x => x.Age);

Upvotes: 5

qJake
qJake

Reputation: 17139

A List has one component to it, and a Dictionary has two components. You can't simply convert them.

If you want your Dictionary to be <int, object>, where int is the index of the information in your List...

Dictionary<int, object> dict = new Dictionary<int, object>();
myList.ForEach(i => dict.Add(myList.IndexOf(i), i)); // Linq magic!

Replace object with your List type, and make sure you are using System.Linq;.

Or use ToDictionary().

Upvotes: 4

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