Hi,

  I need a regex that matches a string containing words (only the letters of the english alphabet, upper and lower case, and digits) and exclude words like MS, IB, DS etc...

Programming language is Java. I tried with \\w+(?:MS|IB|DS). I would appreciate for your help.

regards,

RB
 

To allow "words" you would need to allow spaces, do you want to allow spaces in this?

If yes:

(?!.*\b(?:MS|IB|DS)\b.*)^[a-zA-Z0-9 ]+$

If no:

(?!.*(?:MS|IB|DS).*)^[a-zA-Z0-9]+$

\w includes the underscore character in case you didn't want to allow that.

ddridik,

I think your pattern will match the word but only if it is the only one on the line (the ^ and $ ensure that).

The way I read the OP's question is that, given a text string such as

I dont like the way that MS uses the IB structure

to locate each individual word EXCEPT the MS and IB. If so, something like

(^|\s)(?!MS|IB|DS)[a-zA-Z0-9]+$?

will result in the required matches.

Susan
 

If that's the case then possibly a modifcation of the pattern to:

\b(?!(?:[MD]S|IB)\b)[a-zA-Z0-9]+\b

I am unable to get a match with:

(^|\s)(?!MS|IB|DS)[a-zA-Z0-9]+$?

Although I see where where you were going with that.

Since it will ignore words with underscores in them, if the asker wants to include those words too:

\b(?!(?:[MD]S|IB)\b)\w+\b

Since words with apostrophes will also be excluded unless you modify the pattern to allow for them:

\b(?!(?:[MD]S|IB)\b)[\w']+\b

Test String:

This is a test of a pattern's efficacy excluding DS, MS, and IB but not IBB or BIB.

Results:

Array
(
    [0] => Array
        (
            [0] => This
            [1] => is
            [2] => a
            [3] => test
            [4] => of
            [5] => a
           [ 6] => pattern's
            [7] => efficacy
           [ 8] => excluding
            [9] => and
            [10] => but
            [11] => not
            [12] => IBB
            [13] => or
            [14] => BIB
        )

)