How to use a conditional statement with regex in PowerShell? - regex

Question

There are about ten lines of data. For each line of data I want to indicate whether that line contains numerals.
How can I print out "yes, this line has numerals" or "no, this line has no numerals" for each and every line, exactly once?
output:
thufir#dur:~/flwor/csv$
thufir#dur:~/flwor/csv$ pwsh import.ps1
no digits
Name
----
people…
thufir#dur:~/flwor/csv$
code:
$text = Get-Content -Raw ./people.csv
[array]::Reverse($text)
$tempAttributes = #()
$collectionOfPeople = #()
ForEach ($line in $text) {
if($line -notmatch '.*?[0-9].*?') {
$tempAttributes += $line
Write-Host "matches digits"
}
else {
Write-Host "no digits"
$newPerson = [PSCustomObject]#{
Name = $line
Attributes = $tempAttributes
}
$tempAttributes = #()
$collectionOfPeople += $newPerson
}
}
$collectionOfPeople
data:
people
joe
phone1
phone2
phone3
sue
cell4
home5
alice
atrib6
x7
y9
z10
The only reason I'm printing "digits" or "no digits" is as a marker to aid in building the object.

Answer 1

You can use the following:
switch -regex -file people.csv {
'\d' { "yes" ; $_ }
default { "no"; $_ }
}
\d is a regex character matching a digit. A switch statement with -regex allows for regex expressions to be used for matching text. The default condition is picked when no other condition is met. $_ is the current line being processed.
switch is generally faster than Get-Content for line by line processing. Since you do want to perform certain actions per line, you likely don’t want to use the -Raw parameter because that will read in all file contents as one single string.
# For Reverse Output
$output = switch -regex -file people.csv {
'\d' { "yes" ; $_ }
default { "no"; $_ }
}
$output[($output.GetUpperBound(0))..0)]