Initialise une nouvelle instance de la classe
Random, à l'aide d'une valeur initiale par défaut qui est fonction du temps.
Espace de noms : System
Assembly : mscorlib (dans mscorlib.dll)
Visual Basic (Déclaration)
Visual Basic (Utilisation)
Dim instance As New Random
public function Random ()
Les nombres générés sont distribués de manière uniforme, chaque nombre ayant la même probabilité d'être retourné.
La valeur initiale par défaut est dérivée de l'horloge système. Toutefois, lors de la génération de nombres aléatoires sur des systèmes hautement performants, la valeur de l'horloge système risque de ne pas produire le comportement escompté. Pour plus d'informations, consultez la section Notes du constructeur Random.
L'exemple de code suivant crée des objets Random avec le constructeur de classe sans paramètre et génère une séquence de valeurs de type Double et d'entiers aléatoires. L'exemple montre qu'une séquence différente est générée lorsque l'objet Random est de nouveau créé avec le constructeur sans paramètre.
' Example of the Random class constructors and Random.NextDouble( )
' method.
Imports System
Imports System.Threading
Imports Microsoft.VisualBasic
Module RandomObjectDemo
' Generate random numbers from the specified Random object.
Sub RunIntNDoubleRandoms( randObj As Random )
' Generate the first six random integers.
Dim j As Integer
For j = 0 To 5
Console.Write( " {0,10} ", randObj.Next( ) )
Next j
Console.WriteLine( )
' Generate the first six random doubles.
For j = 0 To 5
Console.Write( " {0:F8} ", randObj.NextDouble( ) )
Next j
Console.WriteLine( )
End Sub
' Create a Random object with the specified seed.
Sub FixedSeedRandoms( seed As Integer )
Console.WriteLine( vbCrLf & _
"Random numbers from a Random object with " & _
"seed = {0}:", seed )
Dim fixRand As New Random( seed )
RunIntNDoubleRandoms( fixRand )
End Sub
' Create a random object with a timer-generated seed.
Sub AutoSeedRandoms( )
' Wait to allow the timer to advance.
Thread.Sleep( 1 )
Console.WriteLine( vbCrLf & _
"Random numbers from a Random object " & _
"with an auto-generated seed:" )
Dim autoRand As New Random( )
RunIntNDoubleRandoms( autoRand )
End Sub
Sub Main( )
Console.WriteLine( _
"This example of the Random class constructors " & _
"and Random.NextDouble( ) " & vbCrLf & _
"generates the following output." & vbCrLf )
Console.WriteLine( "Create Random " & _
"objects, and then generate and display six " & _
"integers and " & vbCrLf & "six doubles from each." )
FixedSeedRandoms( 123 )
FixedSeedRandoms( 123 )
FixedSeedRandoms( 456 )
FixedSeedRandoms( 456 )
AutoSeedRandoms( )
AutoSeedRandoms( )
AutoSeedRandoms( )
End Sub
End Module
' This example of the Random class constructors and Random.NextDouble( )
' generates the following output.
'
' Create Random objects, and then generate and display six integers and
' six doubles from each.
'
' Random numbers from a Random object with seed = 123:
' 2114319875 1949518561 1596751841 1742987178 1586516133 103755708
' 0.01700087 0.14935942 0.19470390 0.63008947 0.90976122 0.49519146
'
' Random numbers from a Random object with seed = 123:
' 2114319875 1949518561 1596751841 1742987178 1586516133 103755708
' 0.01700087 0.14935942 0.19470390 0.63008947 0.90976122 0.49519146
'
' Random numbers from a Random object with seed = 456:
' 2044805024 1323311594 1087799997 1907260840 179380355 120870348
' 0.21988117 0.21026556 0.39236514 0.42420498 0.24102703 0.47310170
'
' Random numbers from a Random object with seed = 456:
' 2044805024 1323311594 1087799997 1907260840 179380355 120870348
' 0.21988117 0.21026556 0.39236514 0.42420498 0.24102703 0.47310170
'
' Random numbers from a Random object with an auto-generated seed:
' 1920831619 1346865774 2006582766 1968819760 332463652 110770792
' 0.71326689 0.50383335 0.50446082 0.66312569 0.94517193 0.58059287
'
' Random numbers from a Random object with an auto-generated seed:
' 254927927 1205531663 1984850027 110020849 1438111494 1697714106
' 0.19383387 0.52067738 0.74162783 0.35063667 0.31247720 0.38773733
'
' Random numbers from a Random object with an auto-generated seed:
' 736507882 1064197552 1963117288 398705585 396275689 1137173773
' 0.67440084 0.53752140 0.97879483 0.03814764 0.67978248 0.19488178
// Example of the Random class constructors and Random.NextDouble( )
// method.
using System;
using System.Threading;
public class RandomObjectDemo
{
// Generate random numbers from the specified Random object.
static void RunIntNDoubleRandoms( Random randObj )
{
// Generate the first six random integers.
for( int j = 0; j < 6; j++ )
Console.Write( " {0,10} ", randObj.Next( ) );
Console.WriteLine( );
// Generate the first six random doubles.
for( int j = 0; j < 6; j++ )
Console.Write( " {0:F8} ", randObj.NextDouble( ) );
Console.WriteLine( );
}
// Create a Random object with the specified seed.
static void FixedSeedRandoms( int seed )
{
Console.WriteLine(
"\nRandom numbers from a Random object with " +
"seed = {0}:", seed );
Random fixRand = new Random( seed );
RunIntNDoubleRandoms( fixRand );
}
// Create a random object with a timer-generated seed.
static void AutoSeedRandoms( )
{
// Wait to allow the timer to advance.
Thread.Sleep( 1 );
Console.WriteLine(
"\nRandom numbers from a Random object " +
"with an auto-generated seed:" );
Random autoRand = new Random( );
RunIntNDoubleRandoms( autoRand );
}
static void Main( )
{
Console.WriteLine(
"This example of the Random class constructors and " +
"Random.NextDouble( ) \n" +
"generates the following output.\n" );
Console.WriteLine(
"Create Random objects, and then generate and " +
"display six integers and \nsix doubles from each.");
FixedSeedRandoms( 123 );
FixedSeedRandoms( 123 );
FixedSeedRandoms( 456 );
FixedSeedRandoms( 456 );
AutoSeedRandoms( );
AutoSeedRandoms( );
AutoSeedRandoms( );
}
}
/*
This example of the Random class constructors and Random.NextDouble( )
generates the following output.
Create Random objects, and then generate and display six integers and
six doubles from each.
Random numbers from a Random object with seed = 123:
2114319875 1949518561 1596751841 1742987178 1586516133 103755708
0.01700087 0.14935942 0.19470390 0.63008947 0.90976122 0.49519146
Random numbers from a Random object with seed = 123:
2114319875 1949518561 1596751841 1742987178 1586516133 103755708
0.01700087 0.14935942 0.19470390 0.63008947 0.90976122 0.49519146
Random numbers from a Random object with seed = 456:
2044805024 1323311594 1087799997 1907260840 179380355 120870348
0.21988117 0.21026556 0.39236514 0.42420498 0.24102703 0.47310170
Random numbers from a Random object with seed = 456:
2044805024 1323311594 1087799997 1907260840 179380355 120870348
0.21988117 0.21026556 0.39236514 0.42420498 0.24102703 0.47310170
Random numbers from a Random object with an auto-generated seed:
380213349 127379247 1969091178 1983029819 1963098450 1648433124
0.08824121 0.41249688 0.36445811 0.05637512 0.62702451 0.49595560
Random numbers from a Random object with an auto-generated seed:
861793304 2133528783 1947358439 124230908 921262645 1087892791
0.56880819 0.42934091 0.60162512 0.74388610 0.99432979 0.30310005
Random numbers from a Random object with an auto-generated seed:
1343373259 1992194672 1925625700 412915644 2026910487 527352458
0.04937517 0.44618494 0.83879212 0.43139707 0.36163507 0.11024451
*/
// Example of the Random class constructors and Random::NextDouble( )
// method.
using namespace System;
using namespace System::Threading;
// Generate random numbers from the specified Random object.
void RunIntNDoubleRandoms( Random^ randObj )
{
// Generate the first six random integers.
for ( int j = 0; j < 6; j++ )
Console::Write( " {0,10} ", randObj->Next() );
Console::WriteLine();
// Generate the first six random doubles.
for ( int j = 0; j < 6; j++ )
Console::Write( " {0:F8} ", randObj->NextDouble() );
Console::WriteLine();
}
// Create a Random object with the specified seed.
void FixedSeedRandoms( int seed )
{
Console::WriteLine( "\nRandom numbers from a Random object with seed = {0}:", seed );
Random^ fixRand = gcnew Random( seed );
RunIntNDoubleRandoms( fixRand );
}
// Create a random object with a timer-generated seed.
void AutoSeedRandoms()
{
// Wait to allow the timer to advance.
Thread::Sleep( 1 );
Console::WriteLine( "\nRandom numbers from a Random object "
"with an auto-generated seed:" );
Random^ autoRand = gcnew Random;
RunIntNDoubleRandoms( autoRand );
}
int main()
{
Console::WriteLine( "This example of the Random class constructors and Random"
"::NextDouble( ) \ngenerates the following output.\n" );
Console::WriteLine( "Create Random objects, and then generate and "
"display six integers and \nsix doubles from each." );
FixedSeedRandoms( 123 );
FixedSeedRandoms( 123 );
FixedSeedRandoms( 456 );
FixedSeedRandoms( 456 );
AutoSeedRandoms();
AutoSeedRandoms();
AutoSeedRandoms();
}
/*
This example of the Random class constructors and Random::NextDouble( )
generates the following output.
Create Random objects, and then generate and display six integers and
six doubles from each.
Random numbers from a Random object with seed = 123:
2114319875 1949518561 1596751841 1742987178 1586516133 103755708
0.01700087 0.14935942 0.19470390 0.63008947 0.90976122 0.49519146
Random numbers from a Random object with seed = 123:
2114319875 1949518561 1596751841 1742987178 1586516133 103755708
0.01700087 0.14935942 0.19470390 0.63008947 0.90976122 0.49519146
Random numbers from a Random object with seed = 456:
2044805024 1323311594 1087799997 1907260840 179380355 120870348
0.21988117 0.21026556 0.39236514 0.42420498 0.24102703 0.47310170
Random numbers from a Random object with seed = 456:
2044805024 1323311594 1087799997 1907260840 179380355 120870348
0.21988117 0.21026556 0.39236514 0.42420498 0.24102703 0.47310170
Random numbers from a Random object with an auto-generated seed:
1624372556 1894939458 302472229 588108304 23919954 1085111949
0.14595512 0.30162298 0.92267372 0.55707657 0.25430079 0.74143239
Random numbers from a Random object with an auto-generated seed:
2105952511 1753605347 280739490 876793040 1129567796 524571616
0.62652210 0.31846701 0.15984073 0.24458755 0.62160607 0.54857684
Random numbers from a Random object with an auto-generated seed:
440048819 1612271236 259006751 1165477776 87731991 2111514930
0.10708907 0.33531104 0.39700773 0.93209853 0.98891135 0.35572129
*/
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile pour Pocket PC, Windows Mobile pour Smartphone, Windows Server 2003, Windows XP Édition Media Center, Windows XP Professionnel Édition x64, Windows XP SP2, Windows XP Starter Edition
Le .NET Framework ne prend pas en charge toutes les versions de chaque plate-forme. Pour obtenir la liste des versions prises en charge, consultez Configuration requise.
.NET Framework
Prise en charge dans : 2.0, 1.1, 1.0
.NET Compact Framework
Prise en charge dans : 2.0, 1.0