Question

My question is how do you regex something that is NOT what my current regex is.

My regex is: 9\d\d\d\d\d\d\d\d\d

I’m trying to find 10 digit numbers that start with 9.
But now I want to find, those who are opposite to this.

How do i do that? I’m trying to use it with notepad++ regex, find those who are not 10 digit and doest start with 9, and delete them.

I need to delete: everything, regardless of numbers of digits as long as its not 10 digit and doesnt start with 9.

Thank you.

I have a long file that looks like this,

 905664572
 9055148
 9052836956
 9054950806
 9059105646
 905403434
 905654765
 9058618018
 90547214

where i need to get rid of all that is not 10 digit.

while using notepad++

this regex works: 9\d\d\d\d\d\d\d\d\d

this regex doesn’t: 9\d{9} AND ^9(\d{0,9}

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This worked to what I was trying to do:

 (?<!\d)[0-9](\d{0,8})

Answer 1

Your regex is 9\d\d\d\d\d\d\d\d\d and could be shortened to 9\d{9} …

Well, the opposite could be (?!9\d\d\d\d\d\d\d\d\d) or (?!9\d{9}) or 9(?>!\d{9})

edit:
the working express: (?<!\d)9(\d{0,8}|\d{10,})(?=\D)