Simple powershell script to check your regular expression strings.
The reference for creating a regular expression is here
http://www.regular-expressions.info/quickstart.html
PS C:\WINDOWS\system32> $String = 'This is my string'
$expression = [regex]"my"
$expression.Match($String)
Groups : {my}
Success : True
Captures : {my}
Index : 8
Length : 2
Value : my
PS C:\WINDOWS\system32> $String = 'this is my string'
$expression = [regex]"[A-Za-z]"
$expression.Match($String)
Groups : {t}
Success : True
Captures : {t}
Index : 0
Length : 1
Value : t
PS C:\WINDOWS\system32> $String = 'this is my string'
$expression = [regex]"[A-Z]"
$expression.Match($String)
Groups : {}
Success : False
Captures : {}
Index : 0
Length : 0
Value :
The reference for creating a regular expression is here
http://www.regular-expressions.info/quickstart.html
PS C:\WINDOWS\system32> $String = 'This is my string'
$expression = [regex]"my"
$expression.Match($String)
Groups : {my}
Success : True
Captures : {my}
Index : 8
Length : 2
Value : my
PS C:\WINDOWS\system32> $String = 'this is my string'
$expression = [regex]"[A-Za-z]"
$expression.Match($String)
Groups : {t}
Success : True
Captures : {t}
Index : 0
Length : 1
Value : t
PS C:\WINDOWS\system32> $String = 'this is my string'
$expression = [regex]"[A-Z]"
$expression.Match($String)
Groups : {}
Success : False
Captures : {}
Index : 0
Length : 0
Value :