ForVsForeach

ForVsForeach.cs

namespace ForVsForeach
{
    using System.Buffers;
    using System;
    using BenchmarkDotNet.Attributes;
    using BenchmarkDotNet.Configs;
    using BenchmarkDotNet.Jobs;
    using BenchmarkDotNet.Running;
    using System.Collections.Generic;

    public static class Program
    {
        [CoreJob]
        [RankColumn, MemoryDiagnoser]
        public class ForeachVsFor 
        {
            public byte[] _data;
            
            [Params(100, 10000)]
            public int N;
            
            [GlobalSetup]
            public void Setup()
            {
                _data = ArrayPool<byte>.Shared.Rent(N);
                new Random(42).NextBytes(_data);
            }
            
            [Benchmark]
            public void Foreach()
            {
                var list = new List<byte>();
                foreach(var d in _data)
                    list.Add(d);
            }
            
            [Benchmark]
            public void For()
            {
                var list = new List<byte>();
                for(var i = 0; i < N; i++)
                    list.Add(_data[i]);
            }
        }

        public static void Main(string[] args)
        {
            BenchmarkRunner.Run<ForeachVsFor>();
        }
    }
}