Set Operations in LINQ
There are four operators for the set operations, each yielding a result based on different criteria.
Operator | Description | C# Query Expression Syntax | VB Query Expression Syntax |
---|---|---|---|
Distinct | Results a list of unique values from a collection by filtering duplicate data if any | Not Applicable | Distinct |
Except | Compares the values of two collections and return the ones from one collection who are not in the other collection | Not Applicable | Not Applicable |
Intersect | Returns the set of values found t be identical in two separate collections | Not Applicable | Not Applicable |
Union | Combines content of two different collections into a single list that too without any duplicate content | Not Applicable | Not Applicable |
Example of Distinct - Query Expression
VB
Module Module1 Sub Main() Dim classGrades = New System.Collections.Generic.List(Of Integer) From {63, 68, 71, 75, 68, 92, 75} Dim distinctQuery = From grade In classGrades Select grade Distinct Dim sb As New System.Text.StringBuilder("The distinct grades are: ") For Each number As Integer In distinctQuery sb.Append(number & " ") Next MsgBox(sb.ToString()) End Sub End Module
When the above code is compiled and executed, it produces the following result −
The distinct grades are: 63 68 71 75 92
Example of Except - Enumerable.Except Method
C#
using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace Operators { class Program { static void Main(string[] args) { double[] numbers1 = { 2.0, 2.1, 2.2, 2.3, 2.4, 2.5 }; double[] numbers2 = { 2.2 }; IEnumerable<double> onlyInFirstSet = numbers1.Except(numbers2); foreach (double number in onlyInFirstSet) Console.WriteLine(number); Console.ReadLine(); } } }
VB
Module Module1 Sub Main() Dim numbers1() As Double = {2.0, 2.1, 2.2, 2.3, 2.4, 2.5} Dim numbers2() As Double = {2.2} Dim onlyInFirstSet As IEnumerable(Of Double) = numbers1.Except(numbers2) Dim output As New System.Text.StringBuilder For Each number As Double In onlyInFirstSet output.AppendLine(number) Console.WriteLine(number) Next Console.ReadLine() End Sub End Module
When the above code of C# or VB is compiled and executed, it produces the following result −
2 2.1 2.3 2.4 2.5
Example of Intersect - Enumerable.Intersect Method
C#
using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace Operators { class Program { static void Main(string[] args) { int[] id1 = { 44, 26, 92, 30, 71, 38 }; int[] id2 = { 39, 59, 83, 47, 26, 4, 30 }; IEnumerable<int> both = id1.Intersect(id2); foreach (int id in both) Console.WriteLine(id); Console.ReadLine(); } } }
VB
Module Module1 Sub Main() Dim id1() As Integer = {44, 26, 92, 30, 71, 38} Dim id2() As Integer = {39, 59, 83, 47, 26, 4, 30} Dim intersection As IEnumerable(Of Integer) = id1.Intersect(id2) Dim output As New System.Text.StringBuilder For Each id As Integer In intersection output.AppendLine(id) Console.WriteLine(id) Next Console.ReadLine() End Sub End Module
When the above code of C# or VB is compiled and executed, it produces the following result −
26 30
Example of Union - Enumerable.Union Method
C#
using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace Operators { class Program { static void Main(string[] args) { int[] ints1 = { 5, 3, 9, 7, 5, 9, 3, 7 }; int[] ints2 = { 8, 3, 6, 4, 4, 9, 1, 0 }; IEnumerable<int> union = ints1.Union(ints2); foreach (int num in union) { Console.Write("{0} ", num); Console.Write("\n"); } Console.ReadLine(); } } }
VB
Module Module1 Sub Main() Dim ints1() As Integer = {5, 3, 9, 7, 5, 9, 3, 7} Dim ints2() As Integer = {8, 3, 6, 4, 4, 9, 1, 0} Dim union As IEnumerable(Of Integer) = ints1.Union(ints2) Dim output As New System.Text.StringBuilder For Each num As Integer In union output.AppendLine(num & " ") Console.WriteLine(num & " ") Next Console.ReadLine() End Sub End Module
When the above code of C# or VB is compiled and executed, it produces the following result −
5 3 9 7 8 6 4 1 0
linq_query_operators.htm
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