Concatenate Unique Elements of two List and Sort using LINQ

Here’s how to concatenate unique elements of two List<String> and then Sort them using LINQ. Use the Enumerable.Concat method

C#

static void Main(string[] args)
{
List<string> lstOne = 
new List<string>() { "Jack", "Henry", "Amy" };
List<string> lstTwo = 
new List<string>() { "Hill", "Amy", "Anna" };
IEnumerable<string> lstNew = null;
// Concatenate Unique Elements of two List<string>
lstNew = lstOne.Concat(lstTwo).Distinct().OrderBy(x => x);
PrintList(lstNew);
Console.ReadLine();
}

static void PrintList(IEnumerable<string> str)
{
foreach (var s in str)
Console.WriteLine(s);
Console.WriteLine("-------------");
}

VB.NET

Sub Main()
Dim lstOne As New List(Of String)() From {"Jack", "Henry", "Amy"}
Dim lstTwo As New List(Of String)() From {"Hill", "Amy", "Anna"}
Dim lstNew As IEnumerable(Of String) = Nothing
' Concatenate Unique Elements of two List<string>
lstNew = lstOne.Concat(lstTwo).Distinct().OrderBy(Function(x) x)
PrintList(lstNew)
Console.ReadLine()
End Sub

Shared Sub PrintList(ByVal str As IEnumerable(Of String))
For Each s In str
Console.WriteLine(s)
Next s
Console.WriteLine("-------------")
End Sub

OUTPUT



As you can see, Amy is not repeated twice as we called the IEnumerable.Distinct of the concatenated list.