Hello,

How do we write a function ?

Public Function myFunc(byVal a as Integer) as Integer
myFunc=2+a
End function

How do we write a subroutine ?

Public Sub mySub(byref a as string)
a=right(a,1)
End Sub

Thank you.



Fil

Best place to start for function syntax would be to type

get-help about_function

at the powershell prompt.

Subroutines as such do not exist in powershell. Their functionality is
provided by functions and filters
--
Richard Siddaway

Please note that all scripts are supplied "as is" and with no warranty


"Fil" wrote:

> Hello,
>
> How do we write a function ?
>
> Public Function myFunc(byVal a as Integer) as Integer
> myFunc=2+a
> End function
>
> How do we write a subroutine ?
>
> Public Sub mySub(byref a as string)
> a=right(a,1)
> End Sub
>
> Thank you.
>
> Fil

Thank you

"RichS" wrote:

> Best place to start for function syntax would be to type
>
> get-help about_function
>
> at the powershell prompt.
>
> Subroutines as such do not exist in powershell. Their functionality is
> provided by functions and filters
> --
> Richard Siddaway
>
> Please note that all scripts are supplied "as is" and with no warranty
>
>
> "Fil" wrote:
>
> > Hello,
> >
> > How do we write a function ?
> >
> > Public Function myFunc(byVal a as Integer) as Integer
> > myFunc=2+a
> > End function
> >
> > How do we write a subroutine ?
> >
> > Public Sub mySub(byref a as string)
> > a=right(a,1)
> > End Sub
> >
> > Thank you.
> >
> > Fil

"Fil" <Fil@discussions.microsoft.com> wrote in message
news:3F0A9577-BAAB-4F0F-A976-8120309E4550@microsoft.com...
> Hello,
>
> How do we write a function ?
>
> Public Function myFunc(byVal a as Integer) as Integer
> myFunc=2+a
> End function

function myFunc([int]$value = 0) {
$result = 2 + $value
foreach ($arg in $args) {
$result += [int]$arg
}
$result
}

65 > myfunc
2
66 > myfunc 2
4
67 > myfunc -value 4
6
68 > myfunc 2 3 4 5
16

The first call takes advantage of specifying a default value for the Value
parameter. The second passes in 2 note that you don't use parens when
calling your own functions. Think of them really as funclets i.e. script
based cmdlets and you don't invoke cmdlets by putting parameters in parens.
The third shows that you can even specify parameters by name just like with
a cmdlet which allows the user to put them in any order. The fourth example
shows that $args is always there to collect any "extra" parameters specified
to your function.

>
> How do we write a subroutine ?
>
> Public Sub mySub(byref a as string)
> a=right(a,1)
> End Sub

function mySub([ref]$a) {
$a.value = $a.Value.SubString(0, $a.Value.Length-1)
}

Call it like so:

$msg = "Hello World"
mySub ([ref]$msg)
$msg
Hello Worl

This demonstrates using by ref parameters. In PoSH a function can "write
output" or not so the distinction between function and subroutine doesn't
really apply. Also keep in mind that any statement that doesn't capture
output, effectively places that output as part of the function's output
e.g.:

function Sum([int]$value = 0) {
"Debug msg: `$value is $value"
$value + 2
}

50 > $result = Sum 3
51 > $result
Debug msg: $value is 3
5

You can fix this like so:

function Sum([int]$value = 0) {
Write-Debug "Debug msg: `$value is $value"
$value + 2
}

Whether or not you see the debug message depends on what you
$DebugPreference variable is set to.

--
Keith

Thank you.

"Keith Hill [MVP]" wrote:

> "Fil" <Fil@discussions.microsoft.com> wrote in message
> news:3F0A9577-BAAB-4F0F-A976-8120309E4550@microsoft.com...
> > Hello,
> >
> > How do we write a function ?
> >
> > Public Function myFunc(byVal a as Integer) as Integer
> > myFunc=2+a
> > End function
>
> function myFunc([int]$value = 0) {
> $result = 2 + $value
> foreach ($arg in $args) {
> $result += [int]$arg
> }
> $result
> }
>
> 65 > myfunc
> 2
> 66 > myfunc 2
> 4
> 67 > myfunc -value 4
> 6
> 68 > myfunc 2 3 4 5
> 16
>
> The first call takes advantage of specifying a default value for the Value
> parameter. The second passes in 2 note that you don't use parens when
> calling your own functions. Think of them really as funclets i.e. script
> based cmdlets and you don't invoke cmdlets by putting parameters in parens.
> The third shows that you can even specify parameters by name just like with
> a cmdlet which allows the user to put them in any order. The fourth example
> shows that $args is always there to collect any "extra" parameters specified
> to your function.
>
> >
> > How do we write a subroutine ?
> >
> > Public Sub mySub(byref a as string)
> > a=right(a,1)
> > End Sub
>
> function mySub([ref]$a) {
> $a.value = $a.Value.SubString(0, $a.Value.Length-1)
> }
>
> Call it like so:
>
> $msg = "Hello World"
> mySub ([ref]$msg)
> $msg
> Hello Worl
>
> This demonstrates using by ref parameters. In PoSH a function can "write
> output" or not so the distinction between function and subroutine doesn't
> really apply. Also keep in mind that any statement that doesn't capture
> output, effectively places that output as part of the function's output
> e.g.:
>
> function Sum([int]$value = 0) {
> "Debug msg: `$value is $value"
> $value + 2
> }
>
> 50 > $result = Sum 3
> 51 > $result
> Debug msg: $value is 3
> 5
>
> You can fix this like so:
>
> function Sum([int]$value = 0) {
> Write-Debug "Debug msg: `$value is $value"
> $value + 2
> }
>
> Whether or not you see the debug message depends on what you
> $DebugPreference variable is set to.
>
> --
> Keith
>
>
>