Passing an input to a function

[Shellcode47 Participant Topics: 1 Replies: 0 Points: 11Rank: Member]

Hello, I’m just getting used to Powershell. When I execute the script and enter the numbers 4 and 5 in the 2 queries I expect to get 9 at the end of the script but I only get 45. If I pass these numbers directly hard-coded to the function then there are no problems. Does anyone have an idea what I am doing wrong?

PowerShell

function Calc ($a, $b) { $res = $a + $b return $res } $num = Read-Host "Num 1: " $num2 = Read-Host "Num 2: " $res = Calc $num $num2 Write-Host $res

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function Calc ($a, $b) { $res = $a + $b return $res }   $num = Read-Host "Num 1: " $num2 = Read-Host "Num 2: "   $res = Calc $num $num2   Write-Host $res

 

[Matt Bloomfield Participant Topics: 4 Replies: 427 Points: 756Rank: Major Contributor]

What’s happening here is that $a and $b are actually String objects.  So the + operator is joining the string ‘5’ to the string ‘4’ and giving you ’45’.  You need to specify that the inputs are integers:

PowerShell

function Calc ([int]$a, [int]$b) { $res = $a + $b return $res } $num = Read-Host "Num 1: " $num2 = Read-Host "Num 2: " $res = Calc $num $num2 Write-Host $res

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function Calc ([int]$a, [int]$b) { $res = $a + $b return $res } $num = Read-Host "Num 1: " $num2 = Read-Host "Num 2: " $res = Calc $num $num2 Write-Host $res

Note: although I’ve done that in the function defintion, you could also specify the type elsewhere e.g.

PowerShell

function Calc ($a, $b) { $res = $a + $b return $res } [int]$num = Read-Host "Num 1: " [int]$num2 = Read-Host "Num 2: " $res = Calc $num $num2 Write-Host $res

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function Calc ($a, $b) { $res = $a + $b return $res } [int]$num = Read-Host "Num 1: " [int]$num2 = Read-Host "Num 2: " $res = Calc $num $num2 Write-Host $res

or even:

PowerShell

function Calc ($a, $b) { $res = [int]$a + [int]$b return $res } $num = Read-Host "Num 1: " $num2 = Read-Host "Num 2: " $res = Calc $num $num2 Write-Host $res

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function Calc ($a, $b) { $res = [int]$a + [int]$b return $res } $num = Read-Host "Num 1: " $num2 = Read-Host "Num 2: " $res = Calc $num $num2 Write-Host $res

 

 

 

 

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