‫بررسی ویژگی Params Collections در C# 13

namespace CS13Tests;

public static class ParamsCollectionsTests
{
    public static void CallSum() => Console.WriteLine(Sum(1, 2, 3));

    private static int Sum(params int[] values) => values.Sum();
}

namespace CS13Tests
{
  public static class ParamsCollectionsTests
  {
    public static void CallSum()
    {
      Console.WriteLine(ParamsCollectionsTests.Sum(new int[3]
      {
        1,
        2,
        3
      }));
    }

    [NullableContext(1)]
    private static int Sum([ParamArray] params int[] values)
    {
      return ((IEnumerable<int>) values).Sum();
    }
  }
}

namespace CS13Tests;

public static class ParamsCollectionsTests
{
    public static void CallPrintNumbersCS12()
    {
        List<int> numbers = [1, 2, 3];
        PrintNumbersCS12([..numbers]); // array
    }

    private static void PrintNumbersCS12(params int[] array) => Console.WriteLine(string.Join(separator: ", ", array));
}

System.Span<T>
System.ReadOnlySpan<T>
System.Collections.Generic.IEnumerable<T>
System.Collections.Generic.IReadOnlyCollection<T>
System.Collections.Generic.IReadOnlyList<T>
System.Collections.Generic.ICollection<T>
System.Collections.Generic.IList<T>

public static class ParamsCollectionsTests
{
    public static void CallSumCS13() => Console.WriteLine(SumCS13(1, 2, 3));

    private static int SumCS13(params ReadOnlySpan<int> values)
    {
        var sum = 0;

        foreach (var item in values)
        {
            sum += item;
        }

        return sum;
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.CompilerServices;

namespace CS13Tests
{
  public static class ParamsCollectionsTests
  {
    public static void CallSumCS13()
    {
      Console.WriteLine(ParamsCollectionsTests.SumCS13(RuntimeHelpers.CreateSpan<int>(__fieldref (<PrivateImplementationDetails>.4636993D3E1DA4E9D6B8F87B79E8F7C6D018580D52661950EABC3845C5897A4D4))));
    }

    private static int SumCS13([ParamCollection, ScopedRef] ReadOnlySpan<int> values)
    {
      int sum = 0;
      ReadOnlySpan<int> readOnlySpan = values;
      for (int index = 0; index < readOnlySpan.Length; ++index)
      {
        int item = readOnlySpan[index];
        sum += item;
      }
      return sum;
    }
  }
}

namespace CS13Tests;

public static class ParamsCollectionsTests
{
    public static void CallCalculateSumCS13() => Console.WriteLine(CalculateSumCS13(1, 2, 3));

    private static int CalculateSumCS13(params List<int> numbers) => numbers.Sum();
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;

namespace CS13Tests
{
  public static class ParamsCollectionsTests
  {
    public static void CallCalculateSumCS13()
    {
      int num1 = 3;
      List<int> intList = new List<int>(num1);
      CollectionsMarshal.SetCount<int>(intList, num1);
      Span<int> span = CollectionsMarshal.AsSpan<int>(intList);
      int index1 = 0;
      span[index1] = 1;
      int index2 = index1 + 1;
      span[index2] = 2;
      int index3 = index2 + 1;
      span[index3] = 3;
      int num2 = index3 + 1;
      Console.WriteLine(ParamsCollectionsTests.CalculateSumCS13(intList));
    }

    [NullableContext(1)]
    private static int CalculateSumCS13([ParamCollection] List<int> numbers)
    {
      return numbers.Sum();
    }
  }
}

namespace CS13Tests;

public static class ParamsCollectionsTests
{
    public static void WriteNames(params string[] names) => Console.WriteLine(string.Join(separator: ", ", names));

    public static void WriteNames(params ReadOnlySpan<string> names)
        => Console.WriteLine(string.Join(separator: ", ", names));

    public static void WriteNames(params IEnumerable<string> names)
        => Console.WriteLine(string.Join(separator: ", ", names));
}

namespace CS13Tests;

public static class ParamsCollectionsTests
{
    public static void CallWriteNames()
    {
        var persons = new List<Person>
        {
            new(FirstName: "Vahid", LastName: "N"),
            new(FirstName: "User1", LastName: "L1"),
            new(FirstName: "User2", LastName: "L2")
        };

        // IEnumerable overload is used
        WriteNames(persons.Select(person => person.FirstName));

        // array overload is used
        WriteNames(new[]
        {
            "Vahid", "User1", "User2"
        });

        // most efficient overload is used: currently ReadOnlySpan
        WriteNames("Vahid", "User1", "User2");
    }

    private record Person(string FirstName, string LastName);
}