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?

Answer 1

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

Answer 2

Following choices are available

1. Quotes around all arguments (')

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

2. 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