Why does the new line change semantics in PowerShell multi-dimensional array creation?

Asked Dec 21 '18 at 19:00

Active Dec 21 '18 at 20:28

Viewed 50 times

[string[][]] $array = @(
  ,@('one', 'two')
  ,@('three', 'four')
)
$array.ForEach({$_.GetType().Name, $_.Length, ($_ -join '-')})

The result is, as expected :

String[]  # first item is a string array
2         # has 2 elements
one-two   # one and two
String[]  # second item is a string array
2         # has 2 elements
three-four# three and four

But if we do not separate the arrays with a new line :

[string[][]] $array = @(
  ,@('one', 'two'), @('three', 'four')
)

The output becomes:

String[] # there are still 2 arrays
1        # but the first one has now only 1 element
one two  # the two expected elements got concatenated into 1
String[] # second array is ok
2
three-four

Why is that ?
_{PSVersion 5.1.18298.1000}

edited Dec 21 '18 at 20:28

asked Dec 21 '18 at 19:00

Bax

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remove the first comma on your second example – Mike Twc Dec 21 '18 at 19:21
@MikeTwc without the comma it behaves erratically when there is only 1 array – Bax Dec 21 '18 at 19:23
The empty element yields in an empty string in the $array.ForEach... hence "" + @("x","y") returns "x y" – Peter Schneider Dec 21 '18 at 19:23
ok. probably it's a better idea to use arraylist then (adding new tuples with add method) – Mike Twc Dec 21 '18 at 19:40
`$array = @('one', 'two'), @('three', 'four')` – Ansgar Wiechers Dec 21 '18 at 20:05
1

@Bax When you want to create an array from a single element (that element being an array itself) you must use the unary array construction operator (`$array = ,@('a', 'b')`). Otherwise you must not use it (`$array = @('a', 'b'), @('c', 'd')`. – Ansgar Wiechers Dec 21 '18 at 20:17

Why does the new line change semantics in PowerShell multi-dimensional array creation?

0 Answers0