8,329 questions
The square brackets are used to include a set of characters (like "[A-Z]"). Replace those with parentheses:
"08 Nov 2022" -match '[0-3][0-9]\s(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\s\d{4}'
Help with Powershell Regular Expression
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(16, 23%, 11%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ESN%3C/text%3E%3C/svg%3E)
Steven Neville
21
Reputation points
I was asked to write a regular expression for "08 Nov 2022". The day has to be 2 digits, the month has to be 3 letters, and the year has to be 4 digits. You also have to specify a space inbetween the day, month, and year
I came up with: "08 Nov 2022" -match '[0-3][0-9]\s[jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec]\s\d{4}'
When this is executed, it will return false.
I tried the following, each returned true:
"08" -match '[0-3][0-9]'
"Nov" -match '[jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec]'
"2022" -match '\d{4}'
"08 Nov" -match '[0-3][0-9]\s[jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec]'
"Nov 2022" -match '[jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec]\s\d{4}'
But when you combine everything to validate day, month, and year; it returns false.
Does anyone have an idea why this is happening? I have a few friends also looking into this but they don't have an answer for me.
Windows for business | Windows Server | User experience | PowerShell
Accepted answer
-
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(256, 74%, 34%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ERM%3C/text%3E%3C/svg%3E)
Rich Matheisen 47,906 Reputation points2022-11-22T16:45:26.627+00:00 -
Steven Neville 21 Reputation points
2022-11-22T16:48:02.517+00:00 Thank you so much.
My teacher was impressed with how indepth the expression was and gave me full marks even though it didn't work.
He was going to look into why it may not have worked.
-
Rich Matheisen 47,906 Reputation points
2022-11-22T19:28:38.347+00:00 For extra credit, explain why all of these return 'True':
"Nov" -match '[jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec]' "Fov" -match '[jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec]' "|" -match '[jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec]' "Juneteenth" -match '[jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec]'
Sign in to comment -