Splitting a string at all whitespace

Question

I need to split a string at all whitespace, it should ONLY contain the words themselves.

How can I do this in vb.net?

Tabs, Newlines, etc. must all be split

Answer 1

So, after seeing Adam Ralph's post, I suspected his solution of being faster than the Regex solution. Just thought I'd share the results of my testing since I did find it was faster.

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There are really two factors at play (ignoring system variables): number of sub-strings extracted (determined by number of delimiters), and total string length. The very simple scenario plotted below uses "A" as the sub-string delimited by two white space characters (a space followed by tab). This accentuates the effect of number of sub-strings extracted. I went ahead and did some multiple variable testing to arrive at the following general equations for my operating system.

Regex()
t = (28.33*SSL + 572)(SSN/10^6)

Split().Where()
t = (6.23*SSL + 250)(SSN/10^6)

Where t is execution time in milliseconds, SSL is average sub-string length, and SSN is number of sub-strings delimited in string.

These equations can also written as

t = (28.33*SL + 572*SSN)/10^6

and

t = (6.23*SL + 250*SSN)/10^6

where SL is total string length (SL = SSL * SSN)

Conclusion: The Split().Where() solution is faster than Regex(). The major factor is number of sub-strings, while string length plays a minor role. Performance gains are about 2x and 5x for the respective coefficients.

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Here's my testing code (probably way more material than necessary, but it's set-up for getting the multi-variable data I talked about)

using System;
using System.Linq;
using System.Diagnostics;
using System.Text.RegularExpressions;
using System.Windows.Forms;
namespace ConsoleApplication1
{
    class Program
    {
        public enum TestMethods {regex, split};
        [STAThread]
        static void Main(string[] args)
        {
            //Compare TestMethod execution times and output result information
            //to the console at runtime and to the clipboard at program finish (so that data is ready to paste into analysis environment)
            #region Config_Variables
            //Choose test method from TestMethods enumerator (regex or split)
            TestMethods TestMethod = TestMethods.split;
            //Configure RepetitionString
            String RepetitionString =  string.Join(" \t", Enumerable.Repeat("A",100));
            //Configure initial and maximum count of string repetitions (final count may not equal max)
            int RepCountInitial = 100;int RepCountMax = 1000 * 100;

            //Step increment to next RepCount (calculated as 20% increase from current value)
            Func<int, int> Step = x => (int)Math.Round(x / 5.0, 0);
            //Execution count used to determine average speed (calculated to adjust down to 1 execution at long execution times)
            Func<double, int> ExecutionCount = x => (int)(1 + Math.Round(500.0 / (x + 1), 0));
            #endregion

            #region NonConfig_Variables
            string s; 
            string Results = "";
            string ResultInfo; 
            double ResultTime = 1;
            #endregion

            for (int RepCount = RepCountInitial; RepCount < RepCountMax; RepCount += Step(RepCount))
            {
                s = string.Join("", Enumerable.Repeat(RepetitionString, RepCount));
                ResultTime = Test(s, ExecutionCount(ResultTime), TestMethod);
                ResultInfo = ResultTime.ToString() + "\t" + RepCount.ToString() + "\t" + ExecutionCount(ResultTime).ToString() + "\t" + TestMethod.ToString();
                Console.WriteLine(ResultInfo); 
                Results += ResultInfo + "\r\n";
            }
            Clipboard.SetText(Results);
        }
        public static double Test(string s, int iMax, TestMethods Method)
        {
            switch (Method)
            {
                case TestMethods.regex:
                    return Math.Round(RegexRunTime(s, iMax),2);
                case TestMethods.split:
                    return Math.Round(SplitRunTime(s, iMax),2);
                default:
                    return -1;
            }
        }
        private static double RegexRunTime(string s, int iMax)
        {
            Stopwatch sw = new Stopwatch();
            sw.Restart();
            for (int i = 0; i < iMax; i++)
            {
                System.Collections.Generic.IEnumerable<string> ens = Regex.Split(s, @"\s+");
            }
            sw.Stop();
            return Math.Round(sw.ElapsedMilliseconds / (double)iMax, 2);
        }
        private static double SplitRunTime(string s,int iMax)
        {
            Stopwatch sw = new Stopwatch();
            sw.Restart();
            for (int i = 0; i < iMax; i++)
            {
                System.Collections.Generic.IEnumerable<string> ens = s.Split().Where(x => x != string.Empty);
            }
            sw.Stop();
            return Math.Round(sw.ElapsedMilliseconds / (double)iMax, 2);
        }
    }
}