JavaScript Regex to avoid certain pattern in textbox

Question

I have a validation to be done. The below pattern(post Man/PostMan/post Man etc) should not be allowed in my text box.
[P|p](OST|ost).*\s*[M|m][a|A][N|n]\s*(\d.)*

I have to add a few more validations to the same input such as: Allow:

Alphabets, Numbers and the special character "-"

And, must not allow:

Any other special characters
The above written pattern, anywhere I enter in the text box.

So the input

I am waiting for postMan
I am waiting for postMan ###
Post Man has not come , are invalid

whereas,

I am waiting for 123348-12
I hope my question is understandable now, are valid

I have tried the following:

([a-z 0-9 A-Z \\-])\*((?!\b[P|p]\*(OST|ost)\*\\.*\s\*[M|m][a|A][N|n]\s\*(\d.)\*\b))\*([a-z 0-9 A-Z])

But It stops working once it finds a character that does not match. For example:

asdasd 666 # posttt -> it stops validating anything after the special character.

What should my regex pattern be?

What do you mean "it stops working?" Can you show us the code where you use the regex? — Explosion Pills, Jul 13 '16 at 15:13
First of all, ignore case: `/p*(post)*\.*\s*man\s*(\d.)*/i`. Then it meant that I'm not allowed to write `I love that ost man!`? — Thomas Ayoub, Jul 13 '16 at 15:16
This sounds like it may be overly complicated for a single regex. — Jared Smith, Jul 13 '16 at 15:19
Sounds like you need `^(?!.*[P|p]*(OST|ost)*\.*\s*[M|m][a|A][N|n]\s*(\d.)*)[a-zA-Z-]*$` that can be further fixed and enhanced. — Wiktor Stribiżew, Jul 13 '16 at 15:35
Doesn't `*` mean "0 or more times"? Then your entire validation pattern reduces to `[Mm][Aa][Nn]` (I doubt that the `|` is doing what you think it's doing) — mob, Jul 13 '16 at 23:19

score 3 · Answer 1 · answered Jul 14 '16 at 03:18

Description

^(?!.*?[Pp]*(OST|ost)*\.*\s*[Mm][Aa][Nn]\s*(\d.)*)[a-z0-9A-Z-]*$

Regular expression visualization

_{** To see the image better, simply right click the image and select view in new window}

This regular expression will do the following:

not allow your first expression to match anywhere in your string
will then only allow a-z, A-Z, 0-9, and -

I would like to point out that if your string in only going to allow letters, numbers, and a hyphen then the test in your expression for a dot is not necessary. Also the multiple upper and lower case character sets can be removed by using the case insensitive flag.

Example

Live Demo

https://regex101.com/r/oY0hK2/1

Sample text

aWoeed1#fde39393aii
aWoeed1fde39393AII
aWoeed1fde39393AIIpostman 3a

Sample Matches

aWoeed1fde39393AII

Explanation

NODE                     EXPLANATION
--------------------------------------------------------------------------------
  ^                        the beginning of the string
--------------------------------------------------------------------------------
  (?!                      look ahead to see if there is not:
--------------------------------------------------------------------------------
    .*?                      any character except \n (0 or more times
                             (matching the least amount possible))
--------------------------------------------------------------------------------
    [Pp]*                    any character of: 'P', 'p' (0 or more
                             times (matching the most amount
                             possible))
--------------------------------------------------------------------------------
    (                        group and capture to \1 (0 or more times
                             (matching the most amount possible)):
--------------------------------------------------------------------------------
      OST                      'OST'
--------------------------------------------------------------------------------
     |                        OR
--------------------------------------------------------------------------------
      ost                      'ost'
--------------------------------------------------------------------------------
    )*                       end of \1 (NOTE: because you are using a
                             quantifier on this capture, only the
                             LAST repetition of the captured pattern
                             will be stored in \1)
--------------------------------------------------------------------------------
    \.*                      '.' (0 or more times (matching the most
                             amount possible))
--------------------------------------------------------------------------------
    \s*                      whitespace (\n, \r, \t, \f, and " ") (0
                             or more times (matching the most amount
                             possible))
--------------------------------------------------------------------------------
    [Mm]                     any character of: 'M', 'm'
--------------------------------------------------------------------------------
    [Aa]                     any character of: 'A', 'a'
--------------------------------------------------------------------------------
    [Nn]                     any character of: 'N', 'n'
--------------------------------------------------------------------------------
    \s*                      whitespace (\n, \r, \t, \f, and " ") (0
                             or more times (matching the most amount
                             possible))
--------------------------------------------------------------------------------
    (                        group and capture to \2 (0 or more times
                             (matching the most amount possible)):
--------------------------------------------------------------------------------
      \d                       digits (0-9)
--------------------------------------------------------------------------------
      .                        any character except \n
--------------------------------------------------------------------------------
    )*                       end of \2 (NOTE: because you are using a
                             quantifier on this capture, only the
                             LAST repetition of the captured pattern
                             will be stored in \2)
--------------------------------------------------------------------------------
  )                        end of look-ahead
--------------------------------------------------------------------------------
  [a-z0-9A-Z-]*            any character of: 'a' to 'z', '0' to '9',
                           'A' to 'Z', '-' (0 or more times (matching
                           the most amount possible))
--------------------------------------------------------------------------------
  $                        before an optional \n, and the end of the
                           string

JavaScript Regex to avoid certain pattern in textbox

1 Answers1

Description

Example

Explanation