CODEWITHSUNDEEP
javascriptregex
rocky
rocky

Reputation: 45

How to tell regex not to match a group?

I was doing some experiment with regex in my learning process.

Input is : I am ironman and I was batman and I will be superman

I want to match all words except the word batman

I tried [^(batman)]+ but it doesn't match characters a,b,m,n,t anywhere in string

How can I achieve it?

Upvotes: 4

Views: 68

Answers (3)

Federico Piazza
Federico Piazza

Reputation: 30985

You can use the discard technique. For instance, you can use this pattern:

batman|(\w+)

Then you will have the words stored in the capturing group.

Working demo

enter image description here

As you can see in the screenshot, words in green are captured using capturing groups while batman in blue is discarded.

Match information:

MATCH 1
1.  [0-1]   `I`
MATCH 2
1.  [2-4]   `am`
MATCH 3
1.  [5-12]  `ironman`
MATCH 4
1.  [13-16] `and`
MATCH 5
1.  [17-18] `I`
MATCH 6
1.  [19-22] `was`
MATCH 7
1.  [30-33] `and`
MATCH 8
1.  [34-35] `I`
MATCH 9
1.  [36-40] `will`
MATCH 10
1.  [41-43] `be`
MATCH 11
1.  [44-52] `superman`

Another example of discard pattern can be if you want to discard batman and superman, so you can use:

batman|superman|(\w+)

Debuggex does a good job showing this:

Regular expression visualization

Upvotes: 3

Casimir et Hippolyte
Casimir et Hippolyte

Reputation: 89547

Several ways are possible:

with a negative lookahead assertion (?!...) (not followed by):

\b(?!batman\b)\w+

with a capture group (you must take in account only the capture group 1):

\b(?:batman\b|(\w+))

Why your pattern doesn't work:

You wrote [^(batman)] but a character class is only a collection of characters without order, you can't describe substrings inside it. It is the same than [^abmnt()]

Upvotes: 4

Amit Joki
Amit Joki

Reputation: 59232

  • It's good you're learning regex but this is overkill as you can easily leverage javascript's vast supernatural powers.
  • It will be faster and in most cases readable than the equivalent the regex.
  • Exclude Batman at your own cost :)
  • Here's how you do it, without regex. I'm sure someone will post regex answer too.

Okay, enough of bullshit, here's the code:

var words = input.split(" ").filter(function(str){
    return str.toLowerCase() !== "batman";
});

Upvotes: 4

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