In LINQ, Element Operators are helpful to find the first or the last element of a list/collection and can also be used to fetch an element based on its index value.
The following are the different types of element operators available in LINQ.
Topics
- First
- FirstOrDefault
- Last
- LastOrDefault
- ElementAt
- ElementAtOrDefault
- Single
- SingleOrDefault
LINQ First Operator
First Operator can be used to fetch the first element from a list/collection.
outList=my_Datasource.First()
LINQ First Operator Example using C#
using System; using System.Collections.Generic; using System.Linq; namespace LinqExamplesCSharp { class Program { static void Main(string[] args) { String[] my_Items = { "Morning", "Afternoon", "Evening", "Night"}; //Trying to fetch the first element of the list... String result = my_Items.First(); Console.WriteLine(result); Console.ReadLine(); } } }Output: Morning
LINQ First Operator Example using Vb.Net
Module Module1
Sub Main()
Dim my_List As String() = {"Morning", "Afternoon", "Evening", "Night"}
'Trying to fetch the first element of the list...
Dim result As String = my_List.First()
Console.WriteLine(result)
Console.ReadLine()
End Sub
End Module
Output:
Morning
LINQ FirstOrDefault Operator
FirstOrdefault Operator can be used to fetch the first element from a list/collection and in case if there are no values in that list/collection it will return a default value.
Example:
Int default value is 0
Boolean default value is False
outList=my_Datasource.FirstOrDefault()
LINQ FirstOrDefault Operator Example using C#
using System; using System.Collections.Generic; using System.Linq; namespace LinqExamplesCSharp { class Program { static void Main(string[] args) { Int32[] num_Items1 = {10, 20, 30, 40, 50}; Int32[] num_Items2 = { }; //Trying to fetch the first element of the list... Int32 result1 = num_Items1.FirstOrDefault(); Int32 result2 = num_Items2.FirstOrDefault(); Console.WriteLine("Result1 : {0}", result1); Console.WriteLine("Result2 : {0}", result2); Console.ReadLine(); } } }Output: Result1 : 10 Result2 : 0
LINQ FirstOrDefault Operator Example using Vb.Net
Module Module1
Sub Main()
Dim num_Items1 As Int32() = {10, 20, 30, 40, 50}
Dim num_Items2 As Int32() = {}
'Trying to fetch the first element of the list...
Dim result1 As String = num_Items1.FirstOrDefault()
Dim result2 As String = num_Items2.FirstOrDefault()
Console.WriteLine("Result1 : {0}", result1)
Console.WriteLine("Result2 : {0}", result2)
Console.ReadLine()
End Sub
End Module
Output:
Result1 : 10
Result2 : 0
LINQ Last Operator
Last Operator can be used to fetch the last element from a list/collection.
outList=my_Datasource.Last()
LINQ Last Operator Example using C#
using System; using System.Collections.Generic; using System.Linq; namespace LinqExamplesCSharp { class Program { static void Main(string[] args) { String[] my_Items = { "Morning", "Afternoon", "Evening", "Night"}; //Trying to fetch the last element of the list... String result = my_Items.Last(); Console.WriteLine(result); Console.ReadLine(); } } }Output: Night
LINQ Last Operator Example using Vb.Net
Module Module1
Sub Main()
Dim my_List As String() = {"Morning", "Afternoon", "Evening", "Night"}
'Trying to fetch the last element of the list...
Dim result As String = my_List.Last()
Console.WriteLine(result)
Console.ReadLine()
End Sub
End Module
Output:
Night
LINQ LastOrDefault Operator
LastOrdefault Operator can be used to fetch the last element from a list/collection and in case if there are no values in that list/collection it will return a default value.
Example:
Int default value is 0
Boolean default value is False
outList=my_Datasource.LastOrDefault()
LINQ LastOrDefault Operator Example using C#
using System; using System.Collections.Generic; using System.Linq; namespace LinqExamplesCSharp { class Program { static void Main(string[] args) { Int32[] num_Items1 = {10, 20, 30, 40, 50}; Int32[] num_Items2 = { }; //Trying to fetch the last element of the list... Int32 result1 = num_Items1.LastOrDefault(); Int32 result2 = num_Items2.LastOrDefault(); Console.WriteLine("Result1 : {0}", result1); Console.WriteLine("Result2 : {0}", result2); Console.ReadLine(); } } }Output: Result1 : 50 Result2 : 0
LINQ LastOrDefault Operator Example using Vb.Net
Module Module1
Sub Main()
Dim num_Items1 As Int32() = {10, 20, 30, 40, 50}
Dim num_Items2 As Int32() = {}
'Trying to fetch the last element of the list...
Dim result1 As String = num_Items1.LastOrDefault()
Dim result2 As String = num_Items2.LastOrDefault()
Console.WriteLine("Result1 : {0}", result1)
Console.WriteLine("Result2 : {0}", result2)
Console.ReadLine()
End Sub
End Module
Output:
Result1 : 50
Result2 : 0
LINQ ElementAt Operator
ElementAt Operator can be used to fetch an element from a list/collection based on the specified index.
In the list datatype, the index starts from zero.
outList=my_Datasource.ElementAt()
LINQ ElementAt Operator Example using C#
using System; using System.Collections.Generic; using System.Linq; namespace LinqExamplesCSharp { class Program { static void Main(string[] args) { String[] my_Items = { "Morning", "Afternoon", "Evening", "Night"}; //Trying to fetch the element of the list based on index number... String result = my_Items.ElementAt(1); Console.WriteLine(result); Console.ReadLine(); } } }Output: Afternoon
LINQ ElementAt Operator Example using Vb.Net
Module Module1
Sub Main()
Dim my_List As String() = {"Morning", "Afternoon", "Evening", "Night"}
'Trying to fetch the element of the list based on index number...
Dim result As String = my_List.ElementAt(1)
Console.WriteLine(result)
Console.ReadLine()
End Sub
End Module
Output:
Afternoon
LINQ ElementAtOrDefault Operator
ElementAtOrdefault Operator can be used to fetch an element from a list/collection based on the specified index.and in case if that index is not valid, it will return a default value.
Example:
Int default value is 0
Boolean default value is False
outList=my_Datasource.ElementAtOrDefault()
LINQ ElementAtOrDefault Operator Example using C#
using System; using System.Collections.Generic; using System.Linq; namespace LinqExamplesCSharp { class Program { static void Main(string[] args) { Int32[] num_Items1 = {10, 20, 30, 40, 50}; Int32[] num_Items2 = { }; //Trying to fetch the element of the list based on index number... Int32 result1 = num_Items1.ElementAtOrDefault(1); Int32 result2 = num_Items2.ElementatOrDefault(1); Console.WriteLine("Result1 : {0}", result1); Console.WriteLine("Result2 : {0}", result2); Console.ReadLine(); } } }Output: Result1 : 20 Result2 : 0
LINQ ElementAtOrDefault Operator Example using Vb.Net
Module Module1
Sub Main()
Dim num_Items1 As Int32() = {10, 20, 30, 40, 50}
Dim num_Items2 As Int32() = {}
'Trying to fetch the element of the list based on index number...
Dim result1 As String = num_Items1.ElementAtOrDefault()
Dim result2 As String = num_Items2.ElementAtOrDefault()
Console.WriteLine("Result1 : {0}", result1)
Console.WriteLine("Result2 : {0}", result2)
Console.ReadLine()
End Sub
End Module
Output:
Result1 : 20
Result2 : 0
LINQ Single Operator
Single Operator can be used to fetch a single element from a list/collection that actually satisfies a given condition
If the collection has got more than one element in it or no elements in it, then it will throw an exception.
outList=my_Datasource.Single()
LINQ Single Operator Example using C#
using System; using System.Collections.Generic; using System.Linq; namespace LinqExamplesCSharp { class Program { static void Main(string[] args) { String[] my_Items = { "Morning", "Afternoon", "Evening", "Night"}; //Trying to fetch the single element of the list... String result = my_Items.Where(x=>x.Contains("Ni")).Single(); Console.WriteLine(result); Console.ReadLine(); } } }Output: Night
LINQ Single Operator Example using Vb.Net
Module Module1
Sub Main()
Dim my_List As String() = {"Morning", "Afternoon", "Evening", "Night"}
'Trying to fetch the single element of the list...
Dim result As String = my_Lists.Where(Function(x) x.Contains("Ni")).Single()
Console.WriteLine(result)
Console.ReadLine()
End Sub
End Module
Output:
Night
LINQ SingleOrDefault Operator
SingleOrDefault Operator can be used to fetch a single element from a list/collection that actually satisfies a given condition
If the collection has got more than one element in it or no elements in it, then it will return a default value.
Example:
Int default value is 0
Boolean default value is False
outList=my_Datasource.SingleOrDefault()
LINQ SingleOrDefault Operator Example using C#
using System; using System.Collections.Generic; using System.Linq; namespace LinqExamplesCSharp { class Program { static void Main(string[] args) { Int32[] num_Items1 = {10, 20, 30, 40, 50}; Int32[] num_Items2 = { }; //Trying to fetch a single value from the list... Int32 result1 = num_Items1.Where(x=>x>40).SingleOrDefault(); Int32 result2 = num_Items2.Where(x=>x>50).SingleorDefault(); Console.WriteLine("Result1 : {0}", result1); Console.WriteLine("Result2 : {0}", result2); Console.ReadLine(); } } }Output: Result1 : 50 Result2 : 0
LINQ SingleOrDefault Operator Example using Vb.Net
Module Module1
Sub Main()
Dim num_Items1 As Int32() = {10, 20, 30, 40, 50}
Dim num_Items2 As Int32() = {}
'Trying to fetch a single value from the list...
Dim result1 As String = num_Items1.Where(Function(x) x > 40).SingleOrDefault()
Dim result2 As String = num_Items2.Where(Function(x) x > 50).SingleorDefault()
Console.WriteLine("Result1 : {0}", result1)
Console.WriteLine("Result2 : {0}", result2)
Console.ReadLine()
End Sub
End Module
Output:
Result1 : 50
Result2 : 0
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