How to concatenate array of integers into comma separated string

Question

I have two question, acually:

1. How to join array of integers into comma separated string? (1,2,3) => \"1,2,3\"
2. How to convert array of integers t

Answer 1

Next code snippet could help out on understanding:

$arraylist = New-Object 'system.collections.arraylist'
$arraylist.Add(111)           | Out-Null
$arraylist.Add([string]222)   | Out-Null
$arraylist.Add('"' + 3 + '"') | Out-Null
for($i=0; $i -lt $arraylist.Count; $i++ ){
    write-host $i, $arraylist[$i], $arraylist[$i].GetType()
}
write-host ''
$csv = $arraylist -join ','
$csv

Output:

0 111 System.Int32
1 222 System.String
2 "3" System.String

111,222,"3"

Additional view of (un)importance of " double quotes in a string type shows next + operation (sum of integers but concatenation of strings):

    write-host $i, $arraylist[$i], $arraylist[$i].GetType().Name, ($arraylist[$i] + 55) 

gives next output:

0 111 Int32 166
1 222 String 22255
2 "3" String "3"55

111,222,"3"

However, " double quotes have another important and meaningful role in .csv file when imported e.g. to Excel sheet.

Answer 2

I don't if this is correct. Usually, they have powershell2. Just give this a little try.

$a = @()
$strArrayNum=""
for($i=0; $i -lt $arraylist.length; $i++ ){
  $strArrayNum += $element
  $strArrayNum = $i+1 -eq $arraylist.length ? "" : ","
}

$a = $strArrayNum.Split(",")

Answer 3

In your question, you've commented out the following snippet:

($arraylist-join -',')

because it returns the error Cannot convert value "," to type "System.Int32"...

The reason for this is the dash - in front of ','.

In PowerShell, only operators and parameters are prefixed with a dash, and since ',' is neither (it's an argument to an operator), the PowerShell parser gets super confused and tries to treat -',' as a value expression that would result in a negative number.

Just void the dash and you'll be fine:

$arraylist -join ','

---

Finally, you can easily cast an array of integers to an array of strings with the unchecked cast operator -as (PowerShell 3.0 and newer):

$StringArray = 1,2,3,4,5 -as [string[]]

or with an explicit cast (PowerShell 2.0-compatible):

$StringArray = [string[]]@(1,2,3,4,5)

Answer 4

This worked for me:

[String]::Join(",", $arraylist.ToArray())

I got 1,2.

And then the second part:

foreach($number in $arraylist) { $number.ToString() }