Powershell Test if array in one line

Question

I do a get-content on a file. Sometimes there are a lot of lines, but it can happen there is only one line (or even 0)

I was doing something like

$csv = (gc $FileIn)
$lastID = $csv[0].Split(' ')[1] #First Line,2nd column

But with only one line, gc return a string and $csv[0] return the first caracter of the string instead of the complete line, and the following Split fail.

Is it possible to do something like :

$lastID = (is_array($csv)?$csv[0]:$csv).Split(' ')[1]

And to do that only if $csv contains at least a line?

Thx for your help, Tim

Answer 1

There are type operators one can use to test the type of a variable. -is is the one you need. Like so,

$foo = @()        # Array
$bar = "zof"      # String
$foo -is [array]  # Is foo an array?
True              # Yes it is
$foo -is [string] # Is foo a string?
False             # No it is not
$bar -is [array]  # How about bar
False             # Nope, not an array
$bar -is [string] # A string then?
True              # You betcha!

So something like this could beused

if($csv -is [array]) {
    # Stuff for array
} else {
    # Stuff for string
}

Answer 2

Instead of doing:

$csv = (gc $FileIn)

you had to

$csv = @(gc $FileIn)

Now the output will always be an array of strings irrespective of the file having one line or not. The rest of the code will just have to treat $csv as an array of strings. This way is better than having to check if the output is an array etc., at the least in this situation.