Get-Random

Gets a random number, or selects objects randomly from a collection.
Get-Random [[-Maximum] [<Object>]] [-Minimum [<Object>]] [-SetSeed [<Int32]>]] [<CommonParameters>]
Get-Random [-InputObject*] <Object[]> [-Count [<Int32>]] [-SetSeed [<Int32]>]] [<CommonParameters>]

The Get-Random cmdlet gets a randomly selected number. If you submit a collection of objects to Get-Random, it gets one or more randomly selected objects from the collection.

Without parameters or input, a Get-Random command returns a randomly selected 32-bit unsigned integer between 0 (zero) and Int32.MaxValue (0x7FFFFFFF, 2,147,483,647).

You can use the parameters of Get-Random to specify a seed number, minimum and maximum values, and the number of objects returned from a submitted collection.

Parameters
-Count [<Int32>]

Specifies how many objects are returned. The default is 1. If the value of Count exceeds the number of objects in the collection, Get-Random returns all of the objects in random order.

-InputObject <Object[]>

  • This value is required
  • Accepts pipeline input ByValue

Specifies a collection of objects. Get-Random gets randomly selected objects in random order from the collection. Enter the objects, a variable that contains the objects, or a command or expression that gets the objects. You can also pipe a collection of objects to Get-Random.

-Maximum [<Object>]

Specifies a maximum value for the random number. Get-Random returns a value that is less than the maximum (not equal). Enter a 32-bit integer or a double-precision floating-point number, or an object that can be converted to an integer or double, such as a numeric string (“100”). On a 64-bit computer, you can also enter a 64-bit integer.

The value of Maximum must be greater than (not equal to) the value of Minimum.

If the value of Maximum or Minimum is a floating-point number, Get-Random returns a randomly selected floating-point number. If the value of Minimum is a double (a floating-point number), the default value of Maximum is Double.MaxValue. Otherwise, the default value is Int32.MaxValue.

On a 64-bit computer, if the value of Minimum is a 32-bit integer, the default value of Maximum is Int32.MaxValue. If the value of Minimum is a double (a floating-point number), the default value of Maximum is Double.MaxValue. Otherwise, the default value is Int64.MaxValue.

-Minimum [<Object>]

Specifies a minimum value for the random number. Enter a 32-bit integer or a double-precision floating-point number, or an object that can be converted to an integer or double, such as a numeric string (“100”). On a 64-bit computer, you can enter a 64-bit integer. The default value is 0 (zero).

The value of Minimum must be less than (not equal to) the value of Maximum. If the value of Maximum or Minimum is a floating-point number, Get-Random returns a randomly selected floating-point number.

-SetSeed [<Int32]>]

Specifies a seed value for the random number generator. This seed value is used for the current command and for all subsequent Get-Random commands in the current session until you use SetSeed again or close the session. You cannot reset the seed to its default, clock-based value.

The SetSeed parameter is not required. By default, Get-Random uses the system clock to generate a seed value. Because SetSeed results in non-random behavior, it is typically used only when trying to reproduce behavior, such as when debugging or analyzing a script that includes Get-Random commands.

<CommonParameters>

This cmdlet supports the common parameters: Verbose, Debug,ErrorAction, ErrorVariable, WarningAction, WarningVariable,OutBuffer, PipelineVariable, and OutVariable.

Inputs

System.Object

You can pipe one or more objects to Get-Random. Get-Random selects values randomly from the piped objects.

Outputs

System.Int32, System.Int64, System.Double

Get-Random returns an integer or floating-point number, or an object selected randomly from a submitted collection.

Examples
  1. Get a random integer:
    PS C:> Get-Random
    3951433
    

    This command gets a random integer between 0 (zero) and Int32.MaxValue.

  2. Get a random integer between 0 and 99:
    PS C:> Get-Random -Maximum 100
    47
    

    This command gets a random integer between 0 (zero) and 99.

  3. Get a random integer between -100 and 99:
    PS C:> Get-Random -Minimum -100 -Maximum 100
    56
    

    This command gets a random integer between -100 and 99.

  4. Get a random floating-point number:
    PS C:> Get-Random -Minimum 10.7 -Maximum 20.93
    18.08467273887
    

    This command gets a random floating-point number greater than or equal to 10.7 and less than 20.92.

  5. Get a random integer from an array:
    PS C:> Get-Random -InputObject 1, 2, 3, 5, 8, 13
    8
    

    This command gets a randomly selected number from the specified array.

  6. Get several random integers from an array:
    PS C:> Get-Random -InputObject 1, 2, 3, 5, 8, 13 -Count 3
    3
    1
    13
    

    This command gets three randomly selected numbers in random order from an array.

  7. This command returns the entire collection in random order:
    PS C:> Get-Random -InputObject 1, 2, 3, 5, 8, 13 -Count ([int]::MaxValue)
    2
    3
    5
    1
    8
    13
    

    The value of the Count parameter is the MaxValue static property of integers.

    To return an entire collection in random order, enter any number that is greater than or equal to the number of objects in the collection.

  8. Get a random non-numeric value:
    PS C:> Get-Random -InputObject "red", "yellow", "blue"
    yellow
    

    This command returns a random value from a non-numeric collection.

  9. Get a random process:
    PS C:> Get-Process | Get-Random
    
       Handles  NPM(K)    PM(K)      WS(K) VM(M)   CPU(s)     Id ProcessName
       -------  ------    -----      ----- -----   ------     -- -----------
       144           4     2080        488    36     0.48   3164 wmiprvse

    This command gets a randomly selected process from the collection of processes on the computer.

  10. Run commands on remote computers in random order:
    PS C:> Get-Content Servers.txt | Get-Random -Count (Get-Content Servers.txt).Count | foreach {Invoke-Command -ComputerName $_ -Command 'Get-Process PowerShell'}
    

    This command runs a command on a series of remote computers in random order.

  11. Use the SetSeed parameter:
    PS C:> Get-Random -Maximum 100 -SetSeed 23
    
       # Commands with the default seed are pseudorandom
    
    PS C:> Get-Random -Maximum 100
    59
    PS C:> Get-Random -Maximum 100
    65
    PS C:> Get-Random -Maximum 100
    21
    
       # Commands with the same seed are not random
    
    PS C:> Get-Random -Maximum 100 -SetSeed 23
    74
    PS C:> Get-Random -Maximum 100 -SetSeed 23
    74
    PS C:> Get-Random -Maximum 100 -SetSeed 23
    74
    
       # SetSeed results in a repeatable series
    
    PS C:> Get-Random -Maximum 100 -SetSeed 23
    74
    PS C:> Get-Random -Maximum 100
    56
    PS C:> Get-Random -Maximum 100
    84
    PS C:> Get-Random -Maximum 100
    46
    PS C:> Get-Random -Maximum 100 -SetSeed 23
    74
    PS C:> Get-Random -Maximum 100
    56
    PS C:> Get-Random -Maximum 100
    84
    PS C:> Get-Random -Maximum 100
    46
    

    This example shows the effect of using the SetSeed parameter. Because SetSeed produces non-random behavior, it is typically used only to reproduce results, such as when debugging or analyzing a script.

  12. Get random files:
    PS C:> $Files = dir -Path C:* -Recurse
    PS C:> $Sample = $Files | Get-Random -Count 50
    

    These commands get a randomly selected sample of 50 files from the C: drive of the local computer.

  13. Get a random integer less than 10001:
    PS C:> Get-Random 10001
    7600
    

    This command gets a random integer less than 10001. Because the Maximum parameter has position 1, you can omit the parameter name when the value is the first or only unnamed parameter in the command.

  14. Get random 64-bit numbers:
    PS C:> Get-Random -Minimum ([Int64]::MinValue)3738173363251507200
    PS C:> Get-Random -Minimum ([Int32]::MaxValue)
    Minimum (2147483647) cannot be greater than or equal to Maximum (2147483647).
    
           + CategoryInfo          : InvalidArgument: (:) [Get-Random], ArgumentException
           + FullyQualifiedErrorId : MinGreaterThanOrEqualMax,Microsoft.PowerShell.Commands.GetRandomCommand

    These commands attempt to get randomly generated 64-bit numbers.

    The first command succeeds, but the second command fails. When the value of Minimum is a 32-bit integer, the default value of Maximum is Int32.MaxValues. The command fails because the value of Maximum must be greater than the value of Minimum.

Additional Notes
 Get-Random sets a default seed for each session based on the system time clock when the session starts.
 Beginning in Windows PowerShell 3.0, Get-Random supports 64-bit integers. In Windows PowerShell 2.0, all 
 values are cast to System.Int32.