LINQ (Single, SingleOrDefault)

<font color="#429DFF">Programm3r</font>

2.45/5 (3 votes)

Dec 15, 2009

CPOL

22911

I sometimes get asked how to get a single object from a generic list based on a LINQ query. i.e. Performing a LINQ query on a generic collection and then returning only the single instance without looping through the collection. Well this is how I do it:public class Person{ public...


public class Person
{
	public string Name{get;set;}
	public string Surname{get;set;}
	public int Age{get;set;}
}

public class Example
{
	List<Person> people = new List<Person>();
	
	public Example()
	{
		people.Add(new Person()
		{
			Name = "Joe",
			Surname = "Smith",
			Age = 35
		});
		people.Add(new Person()
		{
			Name = "John",
			Surname = "Doe",
			Age = 24
		});	
		people.Add(new Person()
		{
			Name = "Jane",
			Surname = "Doe",
			Age = 48
		});
	}
	
	public Person GetSinglePersonFromList(string name)
	{
                // The single element of the input sequence.
		Person person1 = (from p in people
					where p.Name = name
					select p).Single();

                // The single element of the input sequence, or default(TSource) if the sequence contains no elements.
		Person person2 = (from p in people
					where p.Name = name
					select p).SingleOrDefault();

                return person1;
	}
}

This is something very small, but think that it might help. Kind regards,