JacksonDunstan.com

using System;
using System.Collections.Generic;
using System.Text;
using UnityEngine;
 
public static class ArrayExtensions
{
	public static void ForEach<T>(this T[] array, Action<T> callback)
	{
		for (int i = 0, len = array.Length; i < len; ++i)
		{
			callback(array[i]);
		}
	}
}
 
public class TestScript : MonoBehaviour
{
	private static int delegateSum;
	private static Action<Counter> ForEachDelegate = c => delegateSum += c.Value;
 
	private class Counter
	{
		public int Value;
	}
 
	void Start()
	{
		StringBuilder report = new StringBuilder(10 * 1024);
		report.Append("Size,");
		report.Append("Array For,");
		report.Append("Array While,");
		report.Append("Array Foreach,");
		report.Append("Array ForEach (Uncached),");
		report.Append("Array ForEach (Cached),");
		report.Append("List For,");
		report.Append("List While,");
		report.Append("List foreach,");
		report.Append("List Foreach (Uncached),");
		report.Append("List ForEach (Cached)\n");
		const int numIterations = 100000;
		for (int size = 10; size <= 1000; size *= 10)
		{
			var stopwatch = new System.Diagnostics.Stopwatch();
			var sum = 0;
			var array = new Counter[size];
			for (int i = 0; i < size; ++i)
			{
				array[i] = new Counter() { Value = i };
			}
 
			stopwatch.Reset();
			stopwatch.Start();
			for (var iteration = 0; iteration < numIterations; ++iteration)
			{
				for (int i = 0, len = array.Length; i < len; ++i)
				{
					sum += array[i].Value;
				}
			}
			var arrayForTime = stopwatch.ElapsedMilliseconds;
 
			stopwatch.Reset();
			stopwatch.Start();
			for (var iteration = 0; iteration < numIterations; ++iteration)
			{
				var i = 0;
				var len = array.Length;
				while (i < len)
				{
					sum += array[i].Value;
					++i;
				}
			}
			var arrayWhileTime = stopwatch.ElapsedMilliseconds;
 
			stopwatch.Reset();
			stopwatch.Start();
			for (var iteration = 0; iteration < numIterations; ++iteration)
			{
				foreach (var cur in array)
				{
					sum += cur.Value;
				}
			}
			var arrayForeachTime = stopwatch.ElapsedMilliseconds;
 
			stopwatch.Reset();
			stopwatch.Start();
			for (var iteration = 0; iteration < numIterations; ++iteration)
			{
				array.ForEach(c => sum += c.Value);
			}
			var arrayForEachUncachedTime = stopwatch.ElapsedMilliseconds;
 
			stopwatch.Reset();
			stopwatch.Start();
			for (var iteration = 0; iteration < numIterations; ++iteration)
			{
				array.ForEach(ForEachDelegate);
			}
			var arrayForEachCachedTime = stopwatch.ElapsedMilliseconds;
 
			var list = new List<Counter>(size);
			list.AddRange(array);
 
			stopwatch.Reset();
			stopwatch.Start();
			for (var iteration = 0; iteration < numIterations; ++iteration)
			{
				for (int i = 0, len = list.Count; i < len; ++i)
				{
					sum += list[i].Value;
				}
			}
			var listForTime = stopwatch.ElapsedMilliseconds;
 
			stopwatch.Reset();
			stopwatch.Start();
			for (var iteration = 0; iteration < numIterations; ++iteration)
			{
				var i = 0;
				var len = list.Count;
				while (i < len)
				{
					sum += list[i].Value;
					++i;
				}
			}
			var listWhileTime = stopwatch.ElapsedMilliseconds;
 
			stopwatch.Reset();
			stopwatch.Start();
			for (var iteration = 0; iteration < numIterations; ++iteration)
			{
				foreach (var cur in list)
				{
					sum += cur.Value;
				}
			}
			var listForeachTime = stopwatch.ElapsedMilliseconds;
 
			stopwatch.Reset();
			stopwatch.Start();
			for (var iteration = 0; iteration < numIterations; ++iteration)
			{
				list.ForEach(c => sum += c.Value);
			}
			var listForEachUncachedTime = stopwatch.ElapsedMilliseconds;
 
			stopwatch.Reset();
			stopwatch.Start();
			for (var iteration = 0; iteration < numIterations; ++iteration)
			{
				list.ForEach(ForEachDelegate);
			}
			var listForEachCachedTime = stopwatch.ElapsedMilliseconds;
 
			report.Append(size);
			report.Append(',');
			report.Append(arrayForTime);
			report.Append(',');
			report.Append(arrayWhileTime);
			report.Append(',');
			report.Append(arrayForeachTime);
			report.Append(',');
			report.Append(arrayForEachUncachedTime);
			report.Append(',');
			report.Append(arrayForEachCachedTime);
			report.Append(',');
			report.Append(listForTime);
			report.Append(',');
			report.Append(listWhileTime);
			report.Append(',');
			report.Append(listForeachTime);
			report.Append(',');
			report.Append(listForEachUncachedTime);
			report.Append(',');
			report.Append(listForEachCachedTime);
			report.Append('\n');
		}
		Debug.Log(report.ToString());
	}
}