Get-Random
Gets a random number, or selects objects randomly from a collection.
Syntax
Get-Random
[-SetSeed <Int32>]
[[-Maximum] <Object>]
[-Minimum <Object>]
[-Count <Int32>]
[<CommonParameters>]Get-Random
[-SetSeed <Int32>]
[-InputObject] <Object[]>
[-Count <Int32>]
[<CommonParameters>]Get-Random
[-SetSeed <Int32>]
[-InputObject] <Object[]>
[-Shuffle]
[<CommonParameters>]Description
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.
You can use the parameters of Get-Random to specify the minimum and maximum values, the number of
objects returned from a collection, or a seed number.
Caution
Get-Random doesn't ensure cryptographically secure randomness. The 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 can't reset the seed to its default value.
Deliberately setting the seed results in non-random, repeatable behavior. It should only be used
when trying to reproduce behavior, such as when debugging or analyzing a script that includes
Get-Random commands. Be aware that the seed value could be set by other code in the same
session, such as an imported module.
PowerShell 7.4 includes Get-SecureRandom, which ensures cryptographically secure randomness.
Examples
Example 1: Get a random integer
This command gets a random integer between 0 (zero) and Int32.MaxValue.
Get-Random
3951433Example 2: Get a random integer between 0 and 99
Get-Random -Maximum 100
47Example 3: Get a random integer between -100 and 99
Get-Random -Minimum -100 -Maximum 100
56Example 4: Get a random floating-point number
This command gets a random floating-point number greater than or equal to 10.7 and less than 20.93.
Get-Random -Minimum 10.7 -Maximum 20.93
18.08467273887Example 5: Get a random integer from an array
This command gets a randomly selected number from the specified array.
1, 2, 3, 5, 8, 13 | Get-Random
8Example 6: Get several random integers from an array
This command gets three randomly selected numbers in random order from an array.
1, 2, 3, 5, 8, 13 | Get-Random -Count 3
3
1
13Example 7: Randomize an entire collection
Starting in PowerShell 7.1, you can use the Shuffle parameter to return the entire collection in a random order.
1, 2, 3, 5, 8, 13 | Get-Random -Shuffle
2
3
5
1
8
13Example 8: Get a random non-numeric value
This command returns a random value from a non-numeric collection.
"red", "yellow", "blue" | Get-Random
yellowExample 9: Use the SetSeed parameter
This example shows the effect of using the SetSeed parameter.
Because SetSeed produces non-random behavior, it's typically used only to reproduce results, such as when debugging or analyzing a script.
# Commands with the default seed are pseudorandom
Get-Random -Maximum 100 -SetSeed 23
Get-Random -Maximum 100
Get-Random -Maximum 100
Get-Random -Maximum 100
32
25
93
95
# Commands with the same seed aren't random
Get-Random -Maximum 100 -SetSeed 23
Get-Random -Maximum 100 -SetSeed 23
Get-Random -Maximum 100 -SetSeed 23
32
32
32
# SetSeed results in a repeatable series
Get-Random -Maximum 100 -SetSeed 23
Get-Random -Maximum 100
Get-Random -Maximum 100
Get-Random -Maximum 100
32
25
93
95Example 10: Get random files
These commands get a randomly selected sample of 50 files from the C: drive of the local computer.
$Files = Get-ChildItem -Path C:\* -Recurse
$Sample = $Files | Get-Random -Count 50Example 11: Roll fair dice
This example rolls a fair die 1200 times and counts the outcomes. The first command,
ForEach-Object repeats the call to Get-Random from the piped in numbers (1-6). The results are
grouped by their value with Group-Object and formatted as a table with Select-Object.
1..1200 | ForEach-Object {
1..6 | Get-Random
} | Group-Object | Select-Object Name,Count
Name Count
---- -----
1 206
2 199
3 196
4 226
5 185
6 188Example 12: Use the Count parameter
You can now use the Count parameter without piping objects to Get-Random.
The following example gets three random numbers less than 10.
Get-Random -Count 3 -Maximum 10
9
0
8Example 13: Use the InputObject parameter with an empty string or $null
In this example, the InputObject parameter specifies an array that contains an empty string
('') and $null.
Get-Random -InputObject @('a','',$null)Get-Random returns either a, empty string, or $null. The empty sting displays as a blank line
and $null returns to a PowerShell prompt.
Parameters
-Count
Specifies the number of random objects to return. The default is 1.
When used with InputObject containing a collection:
- Each randomly selected item is returned only once.
- If the value of Count exceeds the number of objects in the collection, all objects in the collection are returned in random order.
| Type: | Int32 |
| Position: | Named |
| Default value: | None |
| Required: | False |
| Accept pipeline input: | False |
| Accept wildcard characters: | False |
-InputObject
Specifies a collection of objects. Get-Random gets randomly selected objects in random order from
the collection up to the number specified by Count. 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.
Beginning in PowerShell 7, the InputObject parameter accepts arrays that can contain an empty
string or $null. The array can be sent down the pipeline or as an InputObject parameter value.
| Type: | Object[] |
| Position: | 0 |
| Default value: | None |
| Required: | True |
| Accept pipeline input: | True |
| Accept wildcard characters: | False |
-Maximum
Specifies a maximum value for the random number. Get-Random returns a value that's less than the
maximum (not equal). Enter an integer, a double-precision floating-point number, or an object that
can be converted to an integer or double, such as a numeric string ("100").
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.
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 Int32.MaxValue.
| Type: | Object |
| Position: | 0 |
| Default value: | None |
| Required: | False |
| Accept pipeline input: | False |
| Accept wildcard characters: | False |
-Minimum
Specifies a minimum value for the random number. Enter an integer, a double-precision floating-point number, or an object that can be converted to an integer or double, such as a numeric string ("100"). 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.
| Type: | Object |
| Position: | Named |
| Default value: | None |
| Required: | False |
| Accept pipeline input: | False |
| Accept wildcard characters: | False |
-SetSeed
Specifies a seed value for the random number generator. When you use SetSeed, the cmdlet generates pseudorandom numbers, which isn't cryptographically secure.
Caution
Setting the seed results in non-random behavior. It should only be used when trying to reproduce
behavior, such as when debugging or analyzing a script that includes Get-Random commands.
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 can't reset the seed
to its default value.
| Type: | Nullable<T>[Int32] |
| Position: | Named |
| Default value: | None |
| Required: | False |
| Accept pipeline input: | False |
| Accept wildcard characters: | False |
-Shuffle
Returns the entire collection in a randomized order.
| Type: | SwitchParameter |
| Position: | Named |
| Default value: | None |
| Required: | True |
| Accept pipeline input: | False |
| Accept wildcard characters: | False |
Inputs
You can pipe any object to this cmdlet. It selects values randomly from the piped objects.
Outputs
This cmdlet returns an integer or floating-point number, or an object selected randomly from a submitted collection.
Notes
Get-Random doesn't always return the same data type as the input value. The following table shows
the output type for each of the numeric input types.
| Input Type | Output Type |
|---|---|
| SByte | Double |
| Byte | Double |
| Int16 | Double |
| UInt16 | Double |
| Int32 | Int32 |
| UInt32 | Double |
| Int64 | Int64 |
| UInt64 | Double |
| Double | Double |
| Single | Double |
Beginning in Windows PowerShell 3.0, Get-Random supports 64-bit integers. In Windows PowerShell
2.0, all values are cast to System.Int32.
Beginning in PowerShell 7, the InputObject parameter in the RandomListItemParameterSet
parameter set accepts arrays that contain an empty string or $null. In earlier PowerShell
versions, only the Maximum parameter in the RandomNumberParameterSet parameter set accepted
an empty string or $null.
