powershell: add pscustomobject to ArrayList, but all items goto 1st property

Question

I just created a simple function "f" that adds an pscustomobject element into an arraylist, but when displaying it, result is not what I expected:

$c=New-Object System.Collections.ArrayList($null)
function f([string]$a1,[string]$a2)
{
    $c.Add([PSCustomObject]@{item1=$a1;item2=$a2})
}

f("kkk","aaa")
$c

result is:

item1                                item2
-----                                -----
kkk aaa

It seems to me that both "kkk" and "aaa" goes to item1, if I type

$c.item1

it prints

kkk aaa

Why? I expect item1 to be "kkk" and item2 to be "aaa".

score 2 · Answer 1 · edited May 23 '17 at 11:58

2

have a look at the the powershell gotchas here : https://stackoverflow.com/tags/powershell/info

PowerShell separates function arguments with spaces, not commas.

for those who don't read comments @TheMadTechnician gave you the two correct ways of calling function with arguments in PS : f "kkk" "aaa" or f -a1 "kkk" -a2 "aaa"

edited May 23 '17 at 11:58

Community

1
1

answered May 13 '15 at 05:21

Loïc MICHEL

24,935
9
74
103

3

Probably would be good to show him the correct way to pass his arguments: `f "kkk" "aaa"` or `f -a1 "kkk" -a2 "aaa"` – TheMadTechnician May 13 '15 at 05:23
1

@TheMadTechnician, your comment should be an answer. – Walter Mitty May 13 '15 at 05:37
Thanks for your prompt answer, it's within 10 minutes! Wow! – Immanuel Kant May 13 '15 at 06:18

score 1 · Answer 2 · answered May 13 '15 at 05:47

Ok, as suggested, making an answer. Kayasax really did give the correct answer, even if he didn't help you fix the problem. The reason that both of those strings are assigned to the first property is because you have called your function incorrectly. You have effectively passed 1 argument to the function, that being an array containing two strings. To properly pass multiple arguments to the function either specify them by name (derived by the variable you assign the parameter to within the function, or any declared aliases), or you can pass them without naming them in the order that they are declared in the function, separated by a space.

In your code you are effectively doing this:

f -a1 ("kkk","aaa") -a2

To correct the problem you can either pass the arguments by position:

f "kkk" "aaa"

Or you can pass the arguments by name (order does not matter when passing by name):

f -a1 "kkk" -a2 "aaa"

Doing either of those will result in your desired output.

@ImmanuelKant Instead of writing thanks comment you should upvote this answer if it helped you, that's the way to go here on SO — Loïc MICHEL, May 13 '15 at 06:25

powershell: add pscustomobject to ArrayList, but all items goto 1st property

2 Answers2