Net Framework 4.0 3019 - Best

Contract.Requires(denominator != 0); Contract.Ensures(Contract.Result<int>() == numerator / denominator); return numerator / denominator;

Decoupled composition for plugin architectures — later evolved into System.Composition in .NET 5+. 3.5 Dynamic Language Runtime (DLR) Allowed C# to interop with dynamic languages: net framework 4.0 3019

Enabled data and task parallelism without manual thread management. 3.2 Parallel LINQ (PLINQ) Queries automatically parallelized: Contract

| Workload | Improvement over .NET 3.5 | |----------|----------------------------| | Parallel.For (4 cores) | 3.8x speedup | | Background GC (UI apps) | 40% fewer UI stutters | | LOH allocations | 15% lower fragmentation | | Startup time (NGEN) | 20% faster | Contract.Requires(denominator != 0)

public int Divide(int numerator, int denominator)

Parallel.For(0, 1000, i => Compute(i)); var task = Task.Run(() => LongRunningOperation()); await task; // Not yet native; used ContinueWith in 4.0