Params Collections (csharp-13)

CsharpLangExamples.sln

@@ -61,6 +61,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DefaultLambdaParameters", "
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "LocalFunctionsCsharp7", "LocalFunctionsCsharp7\LocalFunctionsCsharp7.csproj", "{4E00431D-E60B-4866-A78F-091048B911F8}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ParamsCollections", "ParamsCollections\ParamsCollections.csproj", "{5676D9D9-B99F-4B18-B6C6-2C0353655B07}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -183,6 +185,10 @@ Global
 		{4E00431D-E60B-4866-A78F-091048B911F8}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{4E00431D-E60B-4866-A78F-091048B911F8}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{4E00431D-E60B-4866-A78F-091048B911F8}.Release|Any CPU.Build.0 = Release|Any CPU
+		{5676D9D9-B99F-4B18-B6C6-2C0353655B07}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{5676D9D9-B99F-4B18-B6C6-2C0353655B07}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{5676D9D9-B99F-4B18-B6C6-2C0353655B07}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{5676D9D9-B99F-4B18-B6C6-2C0353655B07}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

ParamsCollections/ParamsCollections.csproj

@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <LangVersion>preview</LangVersion>
+  </PropertyGroup>
+
+</Project>

ParamsCollections/Program.cs

@@ -0,0 +1,34 @@
+// See https://aka.ms/new-console-template for more information
+// Console.WriteLine("Hello, World!");
+
+// https://github.com/dotnet/csharplang/issues/7700
+// https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/collection-expressions
+
+void PrintNumbers(params List<int>[] numbersLists) 
+{
+    foreach(var numbers in numbersLists) 
+    {
+        foreach(var number in numbers) 
+        {
+            Console.WriteLine(number);
+        }
+    }
+}
+
+
+PrintNumbers(new List<int> {1, 2, 3}, new List<int> {4, 5, 6}, new List<int> {7, 8, 9});
+/*
+1
+2
+3
+4
+5
+6
+7
+8
+9
+*/
+
+int Sum(params ReadOnlySpan<int> values) => values.ToArray().Sum(x=>x);
+
+Console.WriteLine(Sum(1, 2, 3,4,5,6,7,8,9,10)); // 55

README.md

@@ -8,6 +8,9 @@ Examples of C# programming, with the goal of tracking and staying up-to-date wit
 
 ## Version History
 
+* C# 13
+  * [Params Collections](ParamsCollections/)
+
 * C# 12
   * [Primary constructors](PrimaryConstructors/)
   * [Default values for parameters in lambda expressions](DefaultLambdaParameters/)