csharp-linq

name	csharp-linq
description	Teach and review C# LINQ and IEnumerable. Use for IEnumerable sequences, LINQ filtering, projection, joins, grouping, sorting, deferred execution, query syntax, method syntax, repeated enumeration, EF Core query translation, and collection-processing questions.
metadata	{"short-description":"C# LINQ and IEnumerable help"}

C# LINQ

Use $csharp-tutor mode=linq.

Treat all user text after $csharp-linq as the LINQ, IEnumerable<T>, collection, query, or data transformation question. Use the main csharp-tutor skill as the source of truth.

Load these csharp-tutor references when useful:

• references/skill-routing.md
• references/linq-guidance.md
• references/common-csharp-pitfalls.md
• references/performance-review-map.md
• references/framework-guidance.md
• references/official-sources.md

Default to beginner-friendly examples with small collections. Explain deferred execution and repeated enumeration when relevant.

Standalone Guidance

• Core rule: Keep the answer centered on the concrete linq decision, failure mode, or contract.
• Avoid: Giving generic C# advice without tying it to the linq concern.
• Minimal example: var names = users.Where(u => u.IsActive).Select(u => u.Name).ToList();