Powershell is removing comma from program argument

Question

I want to pass in a comma separated list of values into a script as part of a single switch.

Here is the program.

param(
  [string]$foo
)

Write-Host "[$foo]"

Here is the usage example

PS> .\inputTest.ps1 -foo one,two,three

I would expect the output of this program to be [one,two,three] but instead it is returning [one two three]. This is a problem because I want to use the commas to deliminate the values.

Why is powershell removing the commas, and what do I need to change in order to preserve them?

score 35 · Accepted Answer · answered Aug 16 '12 at 15:35

35

The comma is a special symbol in powershell to denote an array separator.

Just put the arguments in quotes:

inputTest.ps1 -foo "one, two, three"

Alternatively you can 'quote' the comma:

inputTest.ps1 -foo one`,two`,three

answered Aug 16 '12 at 15:35

John Weldon

39,849
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marekzbrzozowa · Answer 2 · 2014-07-31T08:08:17.927

13

Following choices are available

Quotes around all arguments (')

inputTest.ps1 -foo 'one,two,three'
Powershell's escape character before each comma (grave-accent (`))

inputTest.ps1 -foo one`,two`,three

Double quotes around arguments don't change anything !
Single quotes eliminate expanding.
Escape character (grave-accent) eliminates expanding of next character

edited Jul 31 '14 at 08:08

answered Jul 16 '14 at 15:06

marekzbrzozowa

382
1
3
11

2

Double quotes seem to have a weird behaviour. If I use them directly in Powershell, they work, but if I launch Powershell with arguments from another program, they do not work. – NovaLogic Jun 07 '18 at 14:18

score 3 · Answer 3 · answered Aug 16 '12 at 15:36

3

Enclose it in quotes so it interprets it as one variable, not a comma-separated list of three:

PS> .\inputTest.ps1 -foo "one,two,three"

answered Aug 16 '12 at 15:36

David M

71,481
13
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186

score 3 · Answer 4 · answered Oct 20 '14 at 22:12

3

if you are passing parameters from a batch file, then enclse your params as below """Param1,Param2,Param3,Param4"""

answered Oct 20 '14 at 22:12

Manikanta

31
1

score 1 · Answer 5 · edited Sep 27 '22 at 16:18

Powershell will remove the commas and use them to delimitate an array. You can join the array elements back into a string and put a comma between each one.

param(
  [string[]]$foo
)
$foo_joined = $foo -join ","
write-host "[$foo_joined]"

Any spaces between your arguments will be removed, so this:

PS> .\inputTest.ps1 -foo one, two, three

will also output: [one,two,three]

If you need the spaces you'll need quotes, so do this:

PS> .\inputTest.ps1 -foo one,"two is a pair"," three"

if you want to output: [one,two is a pair, three]

Powershell is removing comma from program argument

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