First Query Operator in LINQ using VB.NET
This article defines the basic use of First operator in Linq.
First Operator
The First operator returns the first element in a sequence that satisfies a specified condition. If there is no first elements in the sequence (or no first element that passes the predicate function), use the FirstOrDefault operator instead.
Understanding First
The below defines the
numbers can be an array of integer numbers.
Here is an example of numbers.
Dim numbers As Integer() = {1, 2, 3, 4, 5, 6, 7, 8, 9}
Now using First operator
Dim numbers As Integer() = {1, 2, 3, 4, 5, 6, 7, 8, 9}
Dim first As Integer = numbers.First()
For example
Module Module1
Sub Main()
Dim numbers As Integer() = {1, 2, 3, 4, 5, 6, 7, 8, 9}
Dim first As Integer = numbers.First()
Console.WriteLine("The first number is: " & first)
End Sub
End Module
OUTPUT
Now find out the first even number from the above integer number list.
For Example
Module Module1
Sub Main()
Dim numbers As Integer() = {1, 2, 3, 4, 5, 6, 7, 8, 9}
Dim firstEven As Integer = numbers.First(Function(n) n Mod 2 = 0)
Console.WriteLine("The first even number is " & firstEven)
End Sub
End Module
OUTPUT