PowerShell: function parameter splatting

In PowerShell, the values for function parameters can be passed from an array or a hash table.

An array provides the (positional) values for the function parameters. The hash table also binds a value to the parameter with the same name as the key in the hash table.

In order to use an array or hash table for splatting, the corresponding value needs to be prefixed with an at-sign (@var) rather than the dollar sign ($var) when the function is called:

some-func @anArray another-func @aHashTable

Demonstration

The following code snippet tries to demonstrate how splatting might be used in PowerShell:

function splat {
    param ($p1, $p2, $p3)

  "`$p1 = $p1, `$p2 = $p2, `$p3 = $p3"
}

$hashTable = @{p3 = 'baz'; p1 = 'foo'; p2 = 'bar'}

#
# Invoke splat with a hash table, without splatting
#
splat $hashTable
#
# $p1 = System.Collections.Hashtable, $p2 = , $p3 =

#
# Invoke splat with a hash table, with splatting. Note the use of @ rather than $:
#
splat @hashTable
#
# $p1 = foo, $p2 = bar, $p3 = baz

$array     = 7, 2, 5

#
# Invoke splat with an array, without splatting
#
splat $array
#
# $p1 = 7 2 5, $p2 = , $p3 =

#
# Invoke splat with an array, with splatting
#
splat @array
#
# $p1 = 7, $p2 = 2, $p3 = 5

#
# Use a splatting AND explicit defined parameter:
#
$ht2 = @{p2 = 'world'; p1 = 'hello'}
splat @ht2 -p3 'P3'
#
# $p1 = hello, $p2 = world, $p3 = P3

Github repository about-PowerShell, path: /language/function/parameter/splatting.ps1

PowerShell: function parameter splatting

Demonstration

See also