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    C# Language: all courses in this track

    Guided course · C# Language

    Practical LINQ: Execution, Projection and Grouping

    Understand deferred execution and repeated enumeration. • Use projection, grouping, joins and set operations. • Compare in-memory queries with expression-based queries. • Reason about paging, buffering and measurable query costs.

    Intermediate5 modules · 16 lessons · 3 h 19 min · 5 practice tests · 2 free
    Start the courseSave

    Module 1 · LINQ to Objects

    4 lessons · 36 min
    1. 01Deferred Execution and Repeated Enumeration in LINQ to ObjectsFree, video, 1 practice test9 min
    2. 02Materialization with ToList: Snapshotting LINQ ResultsFree, video, 1 practice test8 min
    3. 03Select vs SelectMany in LINQ to Objects: projection or flattening (included with Full Access), video, 1 practice test9 min
    4. 04Grouping with GroupBy and Common Aggregates in LINQ to Objects (included with Full Access), video, 1 practice test10 min

    Module 2 · Filtering, Joining and Sets

    3 lessons · 34 min
    1. 05Filtering and Ordering: ThenBy, Stability, Nulls and Where-First (included with Full Access)11 min
    2. 06Joins in Memory: Join, GroupJoin, LeftJoin and ToLookup (included with Full Access)12 min
    3. 07Set Operations: Distinct, Union, Intersect, Except and the By Variants (included with Full Access)11 min

    Module 3 · Aggregation, Paging and Performance

    4 lessons · 44 min
    1. 08Aggregation Pitfalls: Overflow, Empty Sequences, MaxBy, CountBy and AggregateBy (included with Full Access)11 min
    2. 09Partitioning and Paging: Skip, Take, Chunk, Index and Keyset Paging (included with Full Access)11 min
    3. 10LINQ Performance You Can Measure: Any vs Count, Allocations and Loops (included with Full Access)11 min
    4. 11Writing Your Own LINQ Operators with yield: Validation, Disposal and Buffering (included with Full Access)11 min

    Module 4 · Practice and Assessment

    1 lesson · 35 min
    1. 12Final Mock Interview: 25 Questions on Practical LINQ (included with Full Access)35 min

    Module 5 · Query Syntax, Expression Trees and Async LINQ

    4 lessons · 50 min
    1. 13Query Syntax vs Method Syntax: What the Compiler Turns from, let and group Into (included with Full Access)12 min
    2. 14IEnumerable<T> vs IQueryable<T>: Func, Expression<Func> and Expression Trees (included with Full Access)13 min
    3. 15Dynamic Filters and Sorting with Expression Trees: AND, OR and Safe OrderBy by Name (included with Full Access)12 min
    4. 16Async LINQ over IAsyncEnumerable<T> in .NET 10, and When PLINQ Helps (included with Full Access)13 min

    Practice tests

    Practical LINQ Interview Check10 questions · 10 min · 10 marksFree

    TechInterviewNotes Editorial Team ·