How to find a specific number of digits in string - powershell

Question

I don't understand the Regex :(
I want to find if a path contains only 7 digits
For an example:
C:\Users\3D Objects\1403036 --> the result should be 1403036
C:\Users\358712\1403036 --> the result should be 1403036
and so on
I have tried:
$FilesPath -match '([\d{1,7}]{7})')
and
$FilesPath -match '(\d{7})')
Currently I am working with that:
$FilesPath = Read-Host -Prompt
if ($Matches[1].Length -eq '7') {
$FolderNumber = $Matches[1]
}
This is not right because there is no match if the path contains the number 3 in the path
If this is the case:
C:\Users\3D Objects\1403036854 --> More than 7 digits the result should be empty
or
C:\Users\3874113353D Objects\1403036 --> Should return result for 1403036
I don't have an array, just want to get if there is a number with exactly 7 digits and don't if contains less or more than 7 digits

Answer 1

You mean something like this?
# as example the paths as aray to loop over
'C:\Users\3D Objects\1403036', 'C:\Users\358712\1403036',
'C:\Users\somewhere\1234567', 'C:\Users\3D Objects\1403036854' | ForEach-Object {
# return the number anchored at the end of the string with exactly 7 digits
([regex]'\D(\d{7})$').Match($_).Groups[1].Value
}
Output:
1403036
1403036
1234567
This:
$path = 'C:\Users\3D Objects\1403036'
$result = ([regex]'\D(\d{7})(?:\D|$)').Match($path).Groups[1].Value
directly assigns the match to variable $result and will be the matching numeric value if it matches or $null. Regex method .Match() does not populate the $matches array.
Using the regex operator, which does populate the $matches array, you can also do this:
if ($path -match '\D(\d{7})(?:\D|$)') {
$result = $matches[1]
}
Regex details:
\D # Match a single character that is NOT a “digit” (any decimal number in any Unicode script)
( # Match the regex below and capture its match into backreference number 1
\d # Match a single character that is a “digit” (any decimal number in any Unicode script)
{7} # Exactly 7 times
)
(?: # Match the regular expression below
# Match this alternative (attempting the next alternative only if this one fails)
\D # Match a single character that is NOT a “digit” (any decimal number in any Unicode script)
|
# Or match this alternative (the entire group fails if this one fails to match)
$ # Assert position at the end of the string, or before the line break at the end of the string, if any (line feed)
)