Master programming syntax, solve interactive challenges & run live code in Syntaxis Explore Arena →
menu_book Course Curriculum (Visual Basic .NET) expand_more
Syntax & Types
Module and Sub Main Dim inference Explicit As type Option Strict Option Infer Nothing Nullable value type String interpolation Const Enum
Operators & Control
If Then Else Select Case For Next For Each While Do Loop Exit statement Continue statement AndAlso OrElse
Procedures
Sub procedure Function procedure ByVal ByRef Optional parameter ParamArray Named arguments Function return Iterator Function Async Function
OOP
Class Constructor New Property ReadOnly property Inheritance Overrides MustInherit Interface Structure Shared member
Collections & LINQ
Array List Of T Dictionary Of K V HashSet Of T Queue Of T Stack Of T LINQ Where LINQ Select LINQ Group By LINQ Order By
Errors & Resources
Try Catch Finally Throw Custom Exception Using statement IDisposable TryCast DirectCast CType SyncLock Debug Assert
Delegates & Events
Delegate Action Func Lambda expression Multiline lambda Event RaiseEvent AddHandler RemoveHandler Handles clause
Advanced .NET
Generic class Generic constraint Extension method Async Await Task WhenAll CancellationToken Iterator Yield XML literals Reflection GetType Attributes
Visual Basic .NET / Collections & LINQ

LINQ Group By

Learn LINQ Group By in Visual Basic .NET through a focused explanation, a dedicated construct-specific example, an engineering boundary, and a mastery check.

10 min read • Intermediate

LINQ Group By is an atomic Visual Basic .NET topic inside Collections & LINQ. This lesson focuses on how the LINQ Group By construct is written, what it changes, and when it is the right tool.

Trace the example line by line. Identify the exact syntax for LINQ Group By, the input state before it runs, and the resulting value, control flow, database state, hardware behavior, or runtime effect afterward. Neighboring lessons use different constructs rather than renamed copies of this one.

Topic-specific example

vbnet-05-09-linq-group-by.vb
vbnet Try It Live 
Dim words={"ant","ape","bear"}
Dim groups=From w In words Group w By key=w(0) Into Group
For Each g In groups : Console.WriteLine($"{g.key}:{g.Group.Count()}") : Next
Edge case / engineering note

For LINQ Group By, test the boundary that belongs to this exact feature rather than a generic failure case. Check invalid or empty input, NULL/unknown state, numeric limits, transaction or exception behavior, synthesis/runtime constraints, ownership/permission rules, or backtracking/control-flow effects where they apply.

Content source & attribution
Original Syntaxis Content · Original Syntaxis Content

Lesson quizzes

LINQ Group By Mastery Check →
← PREVIOUS
LINQ Select
NEXT →
LINQ Order By