Modernize C# snippets (System.Collections) by gewarren · Pull Request #13004 · dotnet/dotnet-api-docs

gewarren · 2026-08-18T22:20:27Z

Contributes to #12713

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File	Preview link
snippets/csharp/System.Collections/ArrayList/Add/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/BinarySearch/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/BinarySearch/source2.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/Clear/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/CopyTo/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/CopyTo/source1.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/GetEnumerator/program.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/IndexOf/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/Insert/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/IsFixedSize/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/IsSynchronized/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/IsSynchronized/source2.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/Item/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/Item/source2.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/LastIndexOf/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/Overview/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/ReadOnly/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/Remove/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/Repeat/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/Reverse/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/Reverse/source1.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/SetRange/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/Sort/arraylist_sort2.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/Sort/arraylist_sort3.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/Sort/source.cs	Preview published page
snippets/csharp/System.Collections/ArrayList/ToArray/arraylist_toarray.cs	Preview published page
snippets/csharp/System.Collections/BitArray/And/source.cs	Preview published page
snippets/csharp/System.Collections/BitArray/CopyTo/source.cs	Preview published page
snippets/csharp/System.Collections/BitArray/Get/source.cs	Preview published page
snippets/csharp/System.Collections/BitArray/Not/source.cs	Preview published page

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Pull request overview

Modernizes System.Collections C# documentation snippets while preserving their demonstrated behavior.

Changes:

Adopts collection expressions, target-typed construction, interpolation, and current formatting.
Adds executable entry points for projects containing multiple examples.
Renames colliding sample types and methods so snippets compile together.

Reviewed changes

Copilot reviewed 139 out of 139 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
`snippets/csharp/System.Collections/Stack/Peek/source.cs`	Modernizes the Peek example.
`snippets/csharp/System.Collections/Stack/Overview/source.cs`	Modernizes the Stack overview.
`snippets/csharp/System.Collections/Stack/IsSynchronized/source2.cs`	Converts the secondary entry point to `Run`.
`snippets/csharp/System.Collections/Stack/IsSynchronized/source.cs`	Modernizes synchronization output.
`snippets/csharp/System.Collections/Stack/IsSynchronized/Project.csproj`	Uses the new shared entry point.
`snippets/csharp/System.Collections/Stack/IsSynchronized/Program.cs`	Runs both Stack examples.
`snippets/csharp/System.Collections/Stack/CopyTo/source.cs`	Modernizes the CopyTo example.
`snippets/csharp/System.Collections/Stack/Clear/source.cs`	Modernizes the Clear example.
`snippets/csharp/System.Collections/SortedList/SetByIndex/source.cs`	Modernizes initialization and output.
`snippets/csharp/System.Collections/SortedList/Remove/source.cs`	Modernizes the Remove example.
`snippets/csharp/System.Collections/SortedList/Overview/source.cs`	Modernizes the overview example.
`snippets/csharp/System.Collections/SortedList/Overview/remarks.cs`	Modernizes remarks initialization.
`snippets/csharp/System.Collections/SortedList/Overview/Project.csproj`	Uses the new shared entry point.
`snippets/csharp/System.Collections/SortedList/Overview/Program.cs`	Runs both overview examples.
`snippets/csharp/System.Collections/SortedList/IsSynchronized/source2.cs`	Converts the secondary entry point to `Run`.
`snippets/csharp/System.Collections/SortedList/IsSynchronized/source.cs`	Modernizes synchronization output.
`snippets/csharp/System.Collections/SortedList/IsSynchronized/Project.csproj`	Uses the new shared entry point.
`snippets/csharp/System.Collections/SortedList/IsSynchronized/Program.cs`	Runs both synchronization examples.
`snippets/csharp/System.Collections/SortedList/IndexOfKey/source.cs`	Modernizes initialization and output.
`snippets/csharp/System.Collections/SortedList/GetByIndex/source.cs`	Modernizes indexed access output.
`snippets/csharp/System.Collections/SortedList/CopyTo/source.cs`	Modernizes the CopyTo example.
`snippets/csharp/System.Collections/SortedList/Contains/source.cs`	Modernizes containment checks.
`snippets/csharp/System.Collections/SortedList/Add/source.cs`	Modernizes the Add example.
`snippets/csharp/System.Collections/SortedList/.ctor/sortedlist_ctorint.cs`	Renames and modernizes the capacity example.
`snippets/csharp/System.Collections/SortedList/.ctor/sortedlist_ctordictionary.cs`	Renames and modernizes the dictionary example.
`snippets/csharp/System.Collections/SortedList/.ctor/sortedlist_ctor.cs`	Renames and modernizes the default example.
`snippets/csharp/System.Collections/SortedList/.ctor/Project.csproj`	Adds an executable .NET 10 project.
`snippets/csharp/System.Collections/SortedList/.ctor/Program.cs`	Runs all constructor examples.
`snippets/csharp/System.Collections/ReadOnlyCollectionBase/Overview/source2.cs`	Renames and modernizes the synchronization example.
`snippets/csharp/System.Collections/ReadOnlyCollectionBase/Overview/readonlycollectionbase.cs`	Modernizes the collection implementation.
`snippets/csharp/System.Collections/ReadOnlyCollectionBase/Overview/Project.csproj`	Adds an executable .NET 10 project.
`snippets/csharp/System.Collections/ReadOnlyCollectionBase/Overview/Program.cs`	Runs both collection examples.
`snippets/csharp/System.Collections/Queue/Overview/source.cs`	Modernizes the Queue overview.
`snippets/csharp/System.Collections/Queue/IsSynchronized/source2.cs`	Converts the secondary entry point to `Run`.
`snippets/csharp/System.Collections/Queue/IsSynchronized/source.cs`	Modernizes synchronization output.
`snippets/csharp/System.Collections/Queue/IsSynchronized/Project.csproj`	Uses the new shared entry point.
`snippets/csharp/System.Collections/Queue/IsSynchronized/Program.cs`	Runs both Queue examples.
`snippets/csharp/System.Collections/Queue/Dequeue/source.cs`	Modernizes the Dequeue example.
`snippets/csharp/System.Collections/Queue/CopyTo/source.cs`	Modernizes the CopyTo example.
`snippets/csharp/System.Collections/Queue/Clear/source.cs`	Modernizes the Clear example.
`snippets/csharp/System.Collections/IStructuralEquatable/Overview/Project.csproj`	Makes the snippet executable.
`snippets/csharp/System.Collections/IStructuralEquatable/Overview/nanexample1.cs`	Modernizes formatting and declarations.
`snippets/csharp/System.Collections/IList/Overview/Project.csproj`	Makes the snippet executable.
`snippets/csharp/System.Collections/IEnumerable/Overview/Project.csproj`	Makes the snippet executable.
`snippets/csharp/System.Collections/IEnumerable/Overview/ienumerator.cs`	Converts the example to top-level statements.
`snippets/csharp/System.Collections/IComparer/reverse.cs`	Modernizes the reverse comparer.
`snippets/csharp/System.Collections/ICollection/IsSynchronized/remarks.cs`	Modernizes construction and locking syntax.
`snippets/csharp/System.Collections/ICollection/IsSynchronized/Project.csproj`	Makes the snippet executable.
`snippets/csharp/System.Collections/Hashtable/Remove/source.cs`	Modernizes the Remove example.
`snippets/csharp/System.Collections/Hashtable/Overview/remarks.cs`	Modernizes remarks initialization.
`snippets/csharp/System.Collections/Hashtable/Overview/Project.csproj`	Makes the project executable.
`snippets/csharp/System.Collections/Hashtable/Overview/Program.cs`	Runs both overview examples.
`snippets/csharp/System.Collections/Hashtable/Overview/hashtable_example.cs`	Modernizes the main overview example.
`snippets/csharp/System.Collections/Hashtable/IsSynchronized/source.cs`	Modernizes synchronized Hashtable setup.
`snippets/csharp/System.Collections/Hashtable/IsSynchronized/remarks.cs`	Converts the remarks entry point to `Run`.
`snippets/csharp/System.Collections/Hashtable/IsSynchronized/Project.csproj`	Uses the new shared entry point.
`snippets/csharp/System.Collections/Hashtable/IsSynchronized/Program.cs`	Runs both synchronization examples.
`snippets/csharp/System.Collections/Hashtable/GetEnumerator/source2.cs`	Modernizes enumeration and output.
`snippets/csharp/System.Collections/Hashtable/CopyTo/source.cs`	Modernizes the CopyTo example.
`snippets/csharp/System.Collections/Hashtable/Contains/source.cs`	Modernizes containment checks.
`snippets/csharp/System.Collections/Hashtable/Clear/source.cs`	Modernizes the Clear example.
`snippets/csharp/System.Collections/Hashtable/Add/source.cs`	Modernizes the Add example.
`snippets/csharp/System.Collections/Hashtable/.ctor/Project.csproj`	Adds an executable .NET 10 project.
`snippets/csharp/System.Collections/Hashtable/.ctor/Program.cs`	Runs all constructor examples.
`snippets/csharp/System.Collections/Hashtable/.ctor/hashtable_ctorintfloat.cs`	Renames and modernizes the capacity/load-factor example.
`snippets/csharp/System.Collections/Hashtable/.ctor/hashtable_ctorint.cs`	Renames and modernizes the capacity example.
`snippets/csharp/System.Collections/Hashtable/.ctor/hashtable_ctordictionaryfloat.cs`	Renames and modernizes the dictionary/load-factor example.
`snippets/csharp/System.Collections/Hashtable/.ctor/hashtable_ctordictionary.cs`	Renames and modernizes the dictionary example.
`snippets/csharp/System.Collections/Hashtable/.ctor/hashtable_ctor.cs`	Renames and modernizes the default example.
`snippets/csharp/System.Collections/DictionaryEntry/Overview/Project.csproj`	Makes the snippet executable.
`snippets/csharp/System.Collections/DictionaryEntry/Overview/DictionaryEntrySample.cs`	Modernizes initialization and output.
`snippets/csharp/System.Collections/DictionaryEntry/Key/remarks.cs`	Renames the sample dictionary type.
`snippets/csharp/System.Collections/DictionaryEntry/Key/Project.csproj`	Adds an executable .NET 10 project.
`snippets/csharp/System.Collections/DictionaryEntry/Key/Program.cs`	Runs both key examples.
`snippets/csharp/System.Collections/DictionaryBase/Overview/Project.csproj`	Adds an executable .NET 10 project.
`snippets/csharp/System.Collections/DictionaryBase/Overview/Program.cs`	Runs both DictionaryBase examples.
`snippets/csharp/System.Collections/Comparer/Overview/Project.csproj`	Makes the snippet executable.
`snippets/csharp/System.Collections/Comparer/Overview/comparercultures.cs`	Modernizes culture comparison output.
`snippets/csharp/System.Collections/CollectionBase/Overview/remarks.cs`	Renames and modernizes the synchronization example.
`snippets/csharp/System.Collections/CollectionBase/Overview/Project.csproj`	Adds an executable .NET 10 project.
`snippets/csharp/System.Collections/CollectionBase/Overview/Program.cs`	Runs both CollectionBase examples.
`snippets/csharp/System.Collections/CaseInsensitiveComparer/Overview/Project.csproj`	Makes the snippet executable.
`snippets/csharp/System.Collections/CaseInsensitiveComparer/Overview/caseinsensitive.cs`	Modernizes Hashtable initialization.
`snippets/csharp/System.Collections/BitArray/Xor/source.cs`	Modernizes the XOR example.
`snippets/csharp/System.Collections/BitArray/Overview/source2.cs`	Converts the locking example to `Run`.
`snippets/csharp/System.Collections/BitArray/Overview/Project.csproj`	Uses the new shared entry point.
`snippets/csharp/System.Collections/BitArray/Overview/Program.cs`	Runs both BitArray examples.
`snippets/csharp/System.Collections/BitArray/Or/source.cs`	Modernizes the OR example.
`snippets/csharp/System.Collections/BitArray/Not/source.cs`	Modernizes the NOT example.
`snippets/csharp/System.Collections/BitArray/Get/source.cs`	Modernizes the Get example.
`snippets/csharp/System.Collections/BitArray/And/source.cs`	Modernizes the AND example.
`snippets/csharp/System.Collections/ArrayList/ToArray/Project.csproj`	Makes the snippet executable.
`snippets/csharp/System.Collections/ArrayList/ToArray/arraylist_toarray.cs`	Modernizes initialization and output.
`snippets/csharp/System.Collections/ArrayList/Sort/source.cs`	Modernizes the default sorting example.
`snippets/csharp/System.Collections/ArrayList/Sort/Project.csproj`	Uses the new shared entry point.
`snippets/csharp/System.Collections/ArrayList/Sort/Program.cs`	Runs all sorting examples.
`snippets/csharp/System.Collections/ArrayList/Sort/arraylist_sort3.cs`	Renames and modernizes the range comparer.
`snippets/csharp/System.Collections/ArrayList/Sort/arraylist_sort2.cs`	Renames and modernizes the comparer.
`snippets/csharp/System.Collections/ArrayList/SetRange/source.cs`	Modernizes the SetRange example.
`snippets/csharp/System.Collections/ArrayList/Reverse/source1.cs`	Modernizes range reversal.
`snippets/csharp/System.Collections/ArrayList/Reverse/source.cs`	Modernizes full-list reversal.
`snippets/csharp/System.Collections/ArrayList/Reverse/Project.csproj`	Uses the new shared entry point.
`snippets/csharp/System.Collections/ArrayList/Reverse/Program.cs`	Runs both reversal examples.
`snippets/csharp/System.Collections/ArrayList/Repeat/source.cs`	Modernizes the Repeat example.
`snippets/csharp/System.Collections/ArrayList/Remove/source.cs`	Modernizes the Remove example.
`snippets/csharp/System.Collections/ArrayList/ReadOnly/source.cs`	Modernizes the read-only wrapper example.
`snippets/csharp/System.Collections/ArrayList/Overview/source.cs`	Modernizes the ArrayList overview.
`snippets/csharp/System.Collections/ArrayList/LastIndexOf/source.cs`	Modernizes reverse-search output.
`snippets/csharp/System.Collections/ArrayList/Item/source2.cs`	Modernizes the scrambling example.
`snippets/csharp/System.Collections/ArrayList/Item/source.cs`	Modernizes indexer usage and handling.
`snippets/csharp/System.Collections/ArrayList/Item/Project.csproj`	Makes the project executable.
`snippets/csharp/System.Collections/ArrayList/Item/Program.cs`	Runs both indexer examples.
`snippets/csharp/System.Collections/ArrayList/IsSynchronized/source2.cs`	Converts the locking example to `Run`.
`snippets/csharp/System.Collections/ArrayList/IsSynchronized/source.cs`	Modernizes synchronization output.
`snippets/csharp/System.Collections/ArrayList/IsSynchronized/Project.csproj`	Uses the new shared entry point.
`snippets/csharp/System.Collections/ArrayList/IsSynchronized/Program.cs`	Runs both synchronization examples.
`snippets/csharp/System.Collections/ArrayList/IndexOf/source.cs`	Modernizes forward-search output.
`snippets/csharp/System.Collections/ArrayList/GetEnumerator/Project.csproj`	Makes the snippet executable.
`snippets/csharp/System.Collections/ArrayList/GetEnumerator/program.cs`	Converts enumeration to top-level code.
`snippets/csharp/System.Collections/ArrayList/CopyTo/source1.cs`	Modernizes the secondary CopyTo example.
`snippets/csharp/System.Collections/ArrayList/CopyTo/source.cs`	Modernizes the primary CopyTo example.
`snippets/csharp/System.Collections/ArrayList/CopyTo/Project.csproj`	Uses the new shared entry point.
`snippets/csharp/System.Collections/ArrayList/CopyTo/Program.cs`	Runs both CopyTo examples.
`snippets/csharp/System.Collections/ArrayList/Clear/source.cs`	Modernizes clearing and capacity output.
`snippets/csharp/System.Collections/ArrayList/BinarySearch/source2.cs`	Modernizes the custom search example.
`snippets/csharp/System.Collections/ArrayList/BinarySearch/source.cs`	Modernizes the standard search example.
`snippets/csharp/System.Collections/ArrayList/BinarySearch/Project.csproj`	Uses the new shared entry point.
`snippets/csharp/System.Collections/ArrayList/BinarySearch/Program.cs`	Runs both search examples.
`snippets/csharp/System.Collections/ArrayList/Add/source.cs`	Modernizes Add and AddRange usage.

Suppressed comments (2)

snippets/csharp/System.Collections/Hashtable/Clear/source.cs:40

This ordinary string prints {de.Key} and {de.Value} literally for every entry rather than displaying the Hashtable contents. Prefix it with $ to interpolate both values.
snippets/csharp/System.Collections/ArrayList/Repeat/source.cs:20
Change “initialize” to “initializes” so it is grammatically parallel with “Creates.”

        // Creates a new ArrayList with seven elements and initialize each element with the string "abc".

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Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com> Co-authored-by: Genevieve Warren <24882762+gewarren@users.noreply.github.com>

BillWagner

This also looks great. One optional suggestion.

And, one forward looking note: We'll probably want to revisit this next year because the next version of C# should include dictionary expressions.

Co-authored-by: Bill Wagner <wiwagn@microsoft.com>

Modernize C# snippets

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dotnet-policy-service Bot assigned gewarren Aug 18, 2026

gewarren requested a balanced review from Copilot August 18, 2026 22:35

Copilot started reviewing on behalf of gewarren August 18, 2026 22:36 View session

Copilot AI reviewed Aug 18, 2026

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gewarren commented Aug 18, 2026

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Comment thread snippets/csharp/System.Collections/ArrayList/Repeat/source.cs Outdated

gewarren commented Aug 18, 2026

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Comment thread snippets/csharp/System.Collections/Hashtable/Clear/source.cs Outdated

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Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com> Co-authored-by: Genevieve Warren <24882762+gewarren@users.noreply.github.com>

gewarren marked this pull request as ready for review August 18, 2026 22:48

gewarren requested a review from a team as a code owner August 18, 2026 22:48

BillWagner approved these changes Aug 19, 2026

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Comment thread snippets/csharp/System.Collections/Hashtable/Contains/source.cs Outdated

Update snippets/csharp/System.Collections/Hashtable/Contains/source.cs

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Co-authored-by: Bill Wagner <wiwagn@microsoft.com>

gewarren enabled auto-merge (squash) August 19, 2026 16:46

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Modernize C# snippets (System.Collections) - #13004

Modernize C# snippets (System.Collections)#13004
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gewarren commented Aug 18, 2026 •

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gewarren commented Aug 18, 2026 •

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