Visual Studio 17.14.0 Preview 3.0
got released earlier today and now you can try out two nice
C# 14.0 features that got released with
.NET 10 Preview 3.0.
Extension Members
We all know about Extension Methods which was there since C# 3.0.
public static class INumberExtensions
{
public static IEnumerable<int> WhereGreaterThan(this IEnumerable<int> source, int threshold)
{
return source.Where(x => x > threshold);
}
public static bool AnyGreaterThan(this IEnumerable<int> source, int threshold)
{
return source.WhereGreaterThan(threshold).Any();
}
}
So here I have some extension methods for IEnumerable<int> which I can call like below:
IEnumerable<int> numbers = [1, 2, 3, 4, 5];
IEnumerable<int> largeNumbers = numbers.WhereGreaterThan(3);
bool hasLargeNumbers = numbers.AnyGreaterThan(3);
With C# 14.0, I can write the same with following syntax. Note: there is no
use of this.
public static class INumberExtensions
{
extension(IEnumerable<int> source)
{
public IEnumerable<int> WhereGreaterThan(int threshold)
=> source.Where(x => x > threshold);
public bool AnyGreaterThan(int threshold)
=> source.WhereGreaterThan(threshold).Any();
}
}
It also supports generic types, something like following:
using System.Numerics;
public static class INumberExtensions
{
extension<T>(IEnumerable<T> source)
where T : INumber<T>
{
public IEnumerable<T> WhereGreaterThan(T threshold)
=> source.Where(x => x > threshold);
public bool AnyGreaterThan(T threshold)
=> source.WhereGreaterThan(threshold).Any();
}
}
Null-Conditional Assignment
Consider the below class.
public class Person
{
public required string Name { get; init; }
public DateOnly? Birthdate { get; set; }
public string? Address { get; set; }
}
And say we need to have a method to update person details.
static void UpdatePerson(Person? person, DateOnly birthdate, string address)
{
if (person is null)
{
return;
}
person.Birthdate = birthdate;
person.Address = address;
}
Here we need to explicitly check whether the person is null before assignment. Now with C# 14.0, we can do this:
static void UpdatePerson(Person person, DateOnly birthdate, string address)
{
person?.Birthdate = birthdate;
person?.Address = address;
}
And this is exactly same as previous code, values will only get set if the person is not null.
Hope this helps.
Happy Coding.
Regards,
Jaliya
