diff --git a/20240913/ConsoleApp1/.vs/ConsoleApp1/v16/.suo b/20240913/ConsoleApp1/.vs/ConsoleApp1/v16/.suo
new file mode 100644
index 0000000..066d009
Binary files /dev/null and b/20240913/ConsoleApp1/.vs/ConsoleApp1/v16/.suo differ
diff --git a/20240913/ConsoleApp1/ConsoleApp1.sln b/20240913/ConsoleApp1/ConsoleApp1.sln
new file mode 100644
index 0000000..e5c2591
--- /dev/null
+++ b/20240913/ConsoleApp1/ConsoleApp1.sln
@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.34729.46
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ConsoleApp1", "ConsoleApp1\ConsoleApp1.csproj", "{5461BED4-2EC9-43D0-A3AB-E98B971326F0}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{5461BED4-2EC9-43D0-A3AB-E98B971326F0}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{5461BED4-2EC9-43D0-A3AB-E98B971326F0}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{5461BED4-2EC9-43D0-A3AB-E98B971326F0}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{5461BED4-2EC9-43D0-A3AB-E98B971326F0}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {76AC5EE9-D38D-4CF6-97C2-567BD327C8C3}
+	EndGlobalSection
+EndGlobal
diff --git a/20240913/ConsoleApp1/ConsoleApp1/App.config b/20240913/ConsoleApp1/ConsoleApp1/App.config
new file mode 100644
index 0000000..56efbc7
--- /dev/null
+++ b/20240913/ConsoleApp1/ConsoleApp1/App.config
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<configuration>
+    <startup> 
+        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2" />
+    </startup>
+</configuration>
\ No newline at end of file
diff --git a/20240913/ConsoleApp1/ConsoleApp1/ConsoleApp1.csproj b/20240913/ConsoleApp1/ConsoleApp1/ConsoleApp1.csproj
new file mode 100644
index 0000000..316e5e3
--- /dev/null
+++ b/20240913/ConsoleApp1/ConsoleApp1/ConsoleApp1.csproj
@@ -0,0 +1,53 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{5461BED4-2EC9-43D0-A3AB-E98B971326F0}</ProjectGuid>
+    <OutputType>Exe</OutputType>
+    <RootNamespace>ConsoleApp1</RootNamespace>
+    <AssemblyName>ConsoleApp1</AssemblyName>
+    <TargetFrameworkVersion>v4.7.2</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
+    <Deterministic>true</Deterministic>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <PlatformTarget>AnyCPU</PlatformTarget>
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <PlatformTarget>AnyCPU</PlatformTarget>
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Data.DataSetExtensions" />
+    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Net.Http" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="Program.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="App.config" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+</Project>
\ No newline at end of file
diff --git a/20240913/ConsoleApp1/ConsoleApp1/Program.cs b/20240913/ConsoleApp1/ConsoleApp1/Program.cs
new file mode 100644
index 0000000..0374d97
--- /dev/null
+++ b/20240913/ConsoleApp1/ConsoleApp1/Program.cs
@@ -0,0 +1,102 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace ConsoleApp1
+{
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            var elemek = new List<Pelda>
+            {
+                new Pelda {X = 11, Y = 12 },
+                new Pelda {X = 51, Y = 98 },
+                new Pelda {X = 17, Y = 18 },
+                new Pelda {X = 11, Y = 52 },
+                new Pelda {X = 14, Y = 18 },
+                new Pelda {X = 41, Y = 16 },
+                new Pelda {X = 12, Y = 12 }
+            };
+
+            var elemek2 = new List<Pelda2>
+            {
+                new Pelda2 {Z = 11, Y = 12 },
+                new Pelda2 {Z = 10, Y = 98 },
+                new Pelda2 {Z = 17, Y = 18 },
+                new Pelda2 {Z = 11, Y = 55 },
+                new Pelda2 {Z = 16, Y = 18 },
+                new Pelda2 {Z = 42, Y = 16 },
+                new Pelda2 {Z = 12, Y = 13 }
+            };
+
+            var eredmeny = (from elem in elemek
+                           group elem by elem.Y into csoport
+                           select csoport);
+
+            var eredmeny2 = elemek.GroupBy(elem => elem.Y);
+
+            
+            Console.WriteLine();
+
+            foreach (var group in eredmeny)
+            {
+                foreach (var item in group)
+                {
+                    Console.WriteLine($"{item.X} {item.Y}");
+                }
+            }
+
+            var eredmeny3 = from elem in elemek
+                            join elem2 in elemek2
+                            on elem.Y equals elem2.Y
+                            select new
+                            {
+                                X = elem.X,
+                                Y = elem.Y,
+                                Z = elem2.Z
+                            };
+
+            var eredmeny4 = elemek.Join(elemek2, i => i.Y, j => j.Y, (i, j) => new
+            {
+                X = i.X,
+                Y = i.Y,
+                Z = j.Z
+            });
+
+            foreach (var item in eredmeny3)
+            {
+                Console.WriteLine($"{item.X},{item.Y},{item.Z}");
+            }
+
+            Console.WriteLine();
+
+            foreach (var item in eredmeny4)
+            {
+                Console.WriteLine($"{item.X},{item.Y},{item.Z}");
+            }
+            Console.WriteLine();
+
+            var eredmeny5 = eredmeny4.Skip(1).Take(2);
+
+            foreach (var item in eredmeny5  )
+            {
+                Console.WriteLine(item);
+            }
+
+        }
+
+        struct Pelda2{
+            public int Y { get; set; }
+            public int Z { get; set; }
+        }
+
+        struct Pelda
+        {
+            public int X { get; set; }
+            public int Y { get; set; }
+        }
+    }
+}
diff --git a/20240913/ConsoleApp1/ConsoleApp1/Properties/AssemblyInfo.cs b/20240913/ConsoleApp1/ConsoleApp1/Properties/AssemblyInfo.cs
new file mode 100644
index 0000000..c260564
--- /dev/null
+++ b/20240913/ConsoleApp1/ConsoleApp1/Properties/AssemblyInfo.cs
@@ -0,0 +1,36 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("ConsoleApp1")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("ConsoleApp1")]
+[assembly: AssemblyCopyright("Copyright ©  2024")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible
+// to COM components.  If you need to access a type in this assembly from
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("5461bed4-2ec9-43d0-a3ab-e98b971326f0")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]
diff --git a/20240913/ConsoleApp1/ConsoleApp1/bin/Debug/ConsoleApp1.exe b/20240913/ConsoleApp1/ConsoleApp1/bin/Debug/ConsoleApp1.exe
new file mode 100644
index 0000000..24c1858
Binary files /dev/null and b/20240913/ConsoleApp1/ConsoleApp1/bin/Debug/ConsoleApp1.exe differ
diff --git a/20240913/ConsoleApp1/ConsoleApp1/bin/Debug/ConsoleApp1.exe.config b/20240913/ConsoleApp1/ConsoleApp1/bin/Debug/ConsoleApp1.exe.config
new file mode 100644
index 0000000..56efbc7
--- /dev/null
+++ b/20240913/ConsoleApp1/ConsoleApp1/bin/Debug/ConsoleApp1.exe.config
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<configuration>
+    <startup> 
+        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2" />
+    </startup>
+</configuration>
\ No newline at end of file
diff --git a/20240913/ConsoleApp1/ConsoleApp1/bin/Debug/ConsoleApp1.pdb b/20240913/ConsoleApp1/ConsoleApp1/bin/Debug/ConsoleApp1.pdb
new file mode 100644
index 0000000..24b2679
Binary files /dev/null and b/20240913/ConsoleApp1/ConsoleApp1/bin/Debug/ConsoleApp1.pdb differ
diff --git a/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/.NETFramework,Version=v4.7.2.AssemblyAttributes.cs b/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/.NETFramework,Version=v4.7.2.AssemblyAttributes.cs
new file mode 100644
index 0000000..3871b18
--- /dev/null
+++ b/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/.NETFramework,Version=v4.7.2.AssemblyAttributes.cs
@@ -0,0 +1,4 @@
+// <autogenerated />
+using System;
+using System.Reflection;
+[assembly: global::System.Runtime.Versioning.TargetFrameworkAttribute(".NETFramework,Version=v4.7.2", FrameworkDisplayName = ".NET Framework 4.7.2")]
diff --git a/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/ConsoleApp1.csproj.AssemblyReference.cache b/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/ConsoleApp1.csproj.AssemblyReference.cache
new file mode 100644
index 0000000..0da8ef2
Binary files /dev/null and b/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/ConsoleApp1.csproj.AssemblyReference.cache differ
diff --git a/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/ConsoleApp1.csproj.CoreCompileInputs.cache b/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/ConsoleApp1.csproj.CoreCompileInputs.cache
new file mode 100644
index 0000000..ee191d7
--- /dev/null
+++ b/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/ConsoleApp1.csproj.CoreCompileInputs.cache
@@ -0,0 +1 @@
+7f4b213b428f4c013f19137338418ee1f5525793
diff --git a/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/ConsoleApp1.csproj.FileListAbsolute.txt b/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/ConsoleApp1.csproj.FileListAbsolute.txt
new file mode 100644
index 0000000..120c22d
--- /dev/null
+++ b/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/ConsoleApp1.csproj.FileListAbsolute.txt
@@ -0,0 +1,7 @@
+C:\Users\szabomarton\Desktop\C#\ProgaOra\20240913\ConsoleApp1\ConsoleApp1\bin\Debug\ConsoleApp1.exe.config
+C:\Users\szabomarton\Desktop\C#\ProgaOra\20240913\ConsoleApp1\ConsoleApp1\bin\Debug\ConsoleApp1.exe
+C:\Users\szabomarton\Desktop\C#\ProgaOra\20240913\ConsoleApp1\ConsoleApp1\bin\Debug\ConsoleApp1.pdb
+C:\Users\szabomarton\Desktop\C#\ProgaOra\20240913\ConsoleApp1\ConsoleApp1\obj\Debug\ConsoleApp1.csproj.AssemblyReference.cache
+C:\Users\szabomarton\Desktop\C#\ProgaOra\20240913\ConsoleApp1\ConsoleApp1\obj\Debug\ConsoleApp1.csproj.CoreCompileInputs.cache
+C:\Users\szabomarton\Desktop\C#\ProgaOra\20240913\ConsoleApp1\ConsoleApp1\obj\Debug\ConsoleApp1.exe
+C:\Users\szabomarton\Desktop\C#\ProgaOra\20240913\ConsoleApp1\ConsoleApp1\obj\Debug\ConsoleApp1.pdb
diff --git a/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/ConsoleApp1.exe b/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/ConsoleApp1.exe
new file mode 100644
index 0000000..24c1858
Binary files /dev/null and b/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/ConsoleApp1.exe differ
diff --git a/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/ConsoleApp1.pdb b/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/ConsoleApp1.pdb
new file mode 100644
index 0000000..24b2679
Binary files /dev/null and b/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/ConsoleApp1.pdb differ
diff --git a/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/DesignTimeResolveAssemblyReferencesInput.cache b/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/DesignTimeResolveAssemblyReferencesInput.cache
new file mode 100644
index 0000000..12b82c1
Binary files /dev/null and b/20240913/ConsoleApp1/ConsoleApp1/obj/Debug/DesignTimeResolveAssemblyReferencesInput.cache differ
diff --git a/linq_anyag b/linq_anyag
index a428da8..38798bf 100644
--- a/linq_anyag
+++ b/linq_anyag
@@ -18,3 +18,22 @@ Ezután vagy az ascending, vagy a descending kulcsszónak kell következnie att
 
 Csoportosítás (good bye)
 
+A csoportosítás query szintaxis esetén a group kulcsszóval kezdődik, amiután meg kell adnunk, hogy pontosan mit szeretnénk csoportba rendezni.
+A példa esetén a kiválasztott elem szerint csoportosítsunk, de állhatna itt egy anonim osztályba leképzés is.
+Ezt követi a by kulcsszó, ami után meg kell adnunk, hogy mi szerint csoportosítunk, majd az into kulcsszó után meg kell adnunk a csoport nevét, amiből ki tudunk majd választani.
+
+A lambda kifejezés szintaxisa látható módon jelen esetben sokkal egyszerűbb, mivel csak azt kell megadnunk, hogy mi szerint rendezünk csoportba, az eredmény pedig már a csoportok sorozata lesz.
+
+Egy csoport elemekből áll.
+
+JOIN
+
+Ezt a műveletet join nak vagy összekapcsolásnak nevezzük. A join műveleteknek több fajtája van. Objeltumok esetén a legkönnyebb at inner mjoin művelet valósítható meg. Et két típus metszetét jelenti.
+
+SOROZAT ÉS ELEM MŰVELETEK
+csak lambda szintaxissal alkalmazhatóak
+
+kihagyás Skip()
+Take() //csak adott számú elem kiválasztása
+
+var eredmeny = elemek.Skip(2).Take(3);