CastTest

In this project I tried to replicate the different ways to cast an object in C#.

For single object there are following:

HardCast

This is the most common way to cast an object, but it is only useful when the object is an instance of the type to be converted, i.e:

public static object John = new Person();

then we can do a hard cast

Person person = (Person)StaticObjects.John;

but if we have an anonymous object we have an exception.

public static object John = new  
{
    Id = Guid.NewGuid(),
    FullName = "John Doe"
};

SafeCast

In this case, doesn't matter if we have an anonymous object, but the result should be nullable.

Person? person = StaticObjects.John as Person;

MatchCast

In this case, as the last one, doesn't matter if we have an anonymous object, the main difference is that we have a condition when we are getting the object casting.

if (StaticObjects.John is Person person)
{
	return person;
}

For collection of objects there are following:

OfType

StaticObjects.People
	.OfType<Person>()
	.ToList();

Cast_As

StaticObjects.People
	.Where(p => p as Person is not null)
	.Cast<Person>()
	.ToList();

Cast_Is

StaticObjects.People
	.Where(p => p is Person)
	.Cast<Person>()
	.ToList();

HardCast_As

StaticObjects.People
	.Where(p => p as Person is not null)
	.Select(p => (Person)p)
	.ToList();

HardCast_Is

StaticObjects.People
	.Where(p => p is Person)
	.Select(p => (Person)p)
	.ToList();

HardCast_TypeOf

StaticObjects.People
	.Where(p => p .GetType() == typeof(Person))
	.Select(p => (Person)p)
	.ToList();

Wrapping up

The best way to cast an object is through SafeCast or MatchCast, as they are interchangeable.
The best option for collection of object is through OfType, since it's simple and readable.

ftinoco/CastTest