class Program
{
private const string string2Reverse = "Loremipsumdolorsitamet,consecteturadipiscingelitUtcondimentumbibendumarcuquiscommodoNullamturpisdolor,interdumaccumsanvestibulumet,elementumnecnibhNammattis,augueactristiquecongue,nuncelitadipiscingdui,uthendreritestmaurisetdiamUtpellentesqueauctorerosinposuereVestibulumvitaeeniminelitmolestietristiquepulvinareumiNullanonquamatellusaccumsanluctusUtvulputatetristiquepretiumLoremipsumdolorsitamet,consecteturadipiscingelitDuisvitaepulvinarvelitCrasvitaemattisdiamSedegettellusnibhSuspendissesempertortoratantevestibulumcursus";
static void Main(string[] args)
{
Thread.Sleep(1000);
Stopwatch sw = Stopwatch.StartNew();
Trace.WriteLine(StrRev(string2Reverse));
Trace.WriteLine("Array.Reverse: " + sw.Elapsed);
Trace.WriteLine("-===================================================================================-");
sw = Stopwatch.StartNew();
Trace.WriteLine(StrRev1(string2Reverse));
Trace.WriteLine("Linq: " + sw.Elapsed);
Trace.WriteLine("-===================================================================================-");
sw = Stopwatch.StartNew();
Trace.WriteLine(StrRev2(string2Reverse));
Trace.WriteLine("StringBuilder: " + sw.Elapsed);
Trace.WriteLine("-===================================================================================-");
sw = Stopwatch.StartNew();
Trace.WriteLine(StrRev3(string2Reverse));
Trace.WriteLine("Array: " + sw.Elapsed);
Trace.WriteLine("-===================================================================================-");
sw = Stopwatch.StartNew();
Trace.WriteLine(StrRev4(string2Reverse));
Trace.WriteLine("Unsafe array: " + sw.Elapsed);
Trace.WriteLine("-===================================================================================-");
sw = Stopwatch.StartNew();
Trace.WriteLine(StrRev5(string2Reverse));
Trace.WriteLine("Unsafe array2: " + sw.Elapsed);
Trace.WriteLine("-===================================================================================-");
Console.ReadKey();
}
public static string StrRev(string source)
{
char []result = source.ToCharArray();
Array.Reverse(result);
return new String(result);
}
public static string StrRev1(string source)
{
return new String(source.Reverse().ToArray());
}
public static string StrRev2(string source)
{
if (source.Length == 1) return source;
StringBuilder sb = new StringBuilder(source.Length);
int i = source.Length – 1;
while(i != -1)
{
sb.Append(source[i–]);
}
return sb.ToString();
}
public static string StrRev3(string source)
{
if (source.Length == 1) return source;
char[] resultArray = new char[source.Length];
int i = 0;
int j = source.Length – 1;
char temp = ”;
while ( i < j )
{
temp = source[i];
resultArray[i] = source[j];
resultArray[j] = temp;
i++;
j–;
}
return new String(resultArray);
}
public static unsafe string StrRev4(string source)
{
if (source.Length == 1) return source;
int i = 0;
int j = source.Length – 1;
fixed (char* sourceArray = source)
{
char temp = ”;
while ( i < j )
{
temp = sourceArray[i];
sourceArray[i] = sourceArray[j];
sourceArray[j] = temp;
i++;
j–;
}
return new String(sourceArray);
}
}
public static unsafe string StrRev5(string source)
{
if (source.Length == 1) return source;
fixed (char* sourceArray = source)
{
char temp = ”;
char* i = sourceArray;
char* j = &sourceArray[source.Length – 1];
while (i < j)
{
temp = *i;
*i = *j;
*j = temp;
i++;
j–;
}
}
return source;
}
}
susrucmulubitsevetnatarotrotrepmesessidnepsuShbinsullettegedeSmaidsittameativsarCtilevranivlupeativsiuDtilegnicsipidarutetcesnoc,tematisrolodmuspimeroLmuiterpeuqitsirtetatupluvtUsutculnasmuccasulletamauqnonalluNimueranivlupeuqitsirteitselomtilenimineeativmulubitseVereusopnisorerotcuaeuqsetnelleptUmaidtesiruamtsetirerdnehtu,iudgnicsipidatilecnun,eugnoceuqitsirtcaeugua,sittammaNhbincenmutnemele,temulubitsevnasmuccamudretni,rolodsiprutmalluNodommocsiuqucramudnebibmutnemidnoctUtilegnicsipidarutetcesnoc,tematisrolodmuspimeroL
Array.Reverse: 00:00:00.0176674
-===================================================================================-
susrucmulubitsevetnatarotrotrepmesessidnepsuShbinsullettegedeSmaidsittameativsarCtilevranivlupeativsiuDtilegnicsipidarutetcesnoc,tematisrolodmuspimeroLmuiterpeuqitsirtetatupluvtUsutculnasmuccasulletamauqnonalluNimueranivlupeuqitsirteitselomtilenimineeativmulubitseVereusopnisorerotcuaeuqsetnelleptUmaidtesiruamtsetirerdnehtu,iudgnicsipidatilecnun,eugnoceuqitsirtcaeugua,sittammaNhbincenmutnemele,temulubitsevnasmuccamudretni,rolodsiprutmalluNodommocsiuqucramudnebibmutnemidnoctUtilegnicsipidarutetcesnoc,tematisrolodmuspimeroL
Linq: 00:00:00.0064376
-===================================================================================-
susrucmulubitsevetnatarotrotrepmesessidnepsuShbinsullettegedeSmaidsittameativsarCtilevranivlupeativsiuDtilegnicsipidarutetcesnoc,tematisrolodmuspimeroLmuiterpeuqitsirtetatupluvtUsutculnasmuccasulletamauqnonalluNimueranivlupeuqitsirteitselomtilenimineeativmulubitseVereusopnisorerotcuaeuqsetnelleptUmaidtesiruamtsetirerdnehtu,iudgnicsipidatilecnun,eugnoceuqitsirtcaeugua,sittammaNhbincenmutnemele,temulubitsevnasmuccamudretni,rolodsiprutmalluNodommocsiuqucramudnebibmutnemidnoctUtilegnicsipidarutetcesnoc,tematisrolodmuspimeroL
StringBuilder: 00:00:00.0017977
-===================================================================================-
susrucmulubitsevetnatarotrotrepmesessidnepsuShbinsullettegedeSmaidsittameativsarCtilevranivlupeativsiuDtilegnicsipidarutetcesnoc,tematisrolodmuspimeroLmuiterpeuqitsirtetatupluvtUsutculnasmuccasulletamauqnonalluNimueranivlupeuqitsirteitselomtilenimineeativmulubitseVereusopnisorerotcuaeuqsetnelleptUmaidtesiruamtsetirerdnehtu,iudgnicsipidatilecnun,eugnoceuqitsirtcaeugua,sittammaNhbincenmutnemele,temulubitsevnasmuccamudretni,rolodsiprutmalluNodommocsiuqucramudnebibmutnemidnoctUtilegnicsipidarutetcesnoc,tematisrolodmuspimeroL
Array: 00:00:00.0017920
-===================================================================================-
susrucmulubitsevetnatarotrotrepmesessidnepsuShbinsullettegedeSmaidsittameativsarCtilevranivlupeativsiuDtilegnicsipidarutetcesnoc,tematisrolodmuspimeroLmuiterpeuqitsirtetatupluvtUsutculnasmuccasulletamauqnonalluNimueranivlupeuqitsirteitselomtilenimineeativmulubitseVereusopnisorerotcuaeuqsetnelleptUmaidtesiruamtsetirerdnehtu,iudgnicsipidatilecnun,eugnoceuqitsirtcaeugua,sittammaNhbincenmutnemele,temulubitsevnasmuccamudretni,rolodsiprutmalluNodommocsiuqucramudnebibmutnemidnoctUtilegnicsipidarutetcesnoc,tematisrolodmuspimeroL
Unsafe array: 00:00:00.0018522
-===================================================================================-
The StrRev4 method changes const string! Wow!
Loremipsumdolorsitamet,consecteturadipiscingelitUtcondimentumbibendumarcuquiscommodoNullamturpisdolor,interdumaccumsanvestibulumet,elementumnecnibhNammattis,augueactristiquecongue,nuncelitadipiscingdui,uthendreritestmaurisetdiamUtpellentesqueauctorerosinposuereVestibulumvitaeeniminelitmolestietristiquepulvinareumiNullanonquamatellusaccumsanluctusUtvulputatetristiquepretiumLoremipsumdolorsitamet,consecteturadipiscingelitDuisvitaepulvinarvelitCrasvitaemattisdiamSedegettellusnibhSuspendissesempertortoratantevestibulumcursus
Unsafe array2: 00:00:00.0017094
-===================================================================================-
As we can see the Array reverse method is the safe and fast enough way to reverse string.
Grigory's space 