Regex, match numbers and then a range of characters

Question

I'm currently attempting to write some relatively simple(?) regex which captures a group of numbers which are then followed by specific characters.

https://regexr.com/4jp9h is a good example, I actually thought it was working but the 4 garlic cloves example chucked a spanner in the works. I've played with not matching whitespace / the spaces but haven't had much luck at all.

All of the other matches are fine, eg: 900g, 900kg, so on and so forth. But I can't for the life of me figure out how to stop the 4 garlic cloves example from matching.

Anyone got any ideas? :)

You want to match d900g or 900gd also ? can you list out what will be desired result for such cases ? — Code Maniac
– Code Maniac, Commented Aug 24, 2019 at 17:31
Please, edit your question and add your test cases with expected result. — Toto
– Toto, Commented Aug 24, 2019 at 17:53

Code Maniac · Accepted Answer · 2019-08-24 17:39:17Z

2

\d+.?[g-k]

Why 4 g matches ?

You have .? which means match anything except new line once ( optional ), also i believe you want to match kg or g

So you can simply use

\d+k?g

\d+ - Match one or more digit
k? - Match k ( optional )
g - Match g

answered Aug 24, 2019 at 17:39

Code Maniac

37.9k5 gold badges44 silver badges65 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Nigel Ren · Accepted Answer · 2019-08-24 18:31:21Z

2

An alternative version is...

\d+[Kk]?[Gg]\s

This is allows Kg, KG, g, G, but also then tries to ensure that there is nothing following directly after it, so in your test set...

there 900G          Match
900gvhello
hello garam masala
test g900gd
900kg               Match
4 garlic cloves

So it doesn't match g900gd or 4 garlic cloves.

As pointed out, the \s on the end may be better with alternatives which match different things.

The fourth bird suggests a non whitespace char (?!\S)

Or an alternative may also be a non word character [^w].

edited Aug 24, 2019 at 18:31

answered Aug 24, 2019 at 18:08

Nigel Ren

57.3k11 gold badges49 silver badges59 bronze badges

1 Comment

Nigel Ren Over a year ago

@Thefourthbird, I wasn't sure of the best way - it may be that or just not a word character ( I tried [^\w]). Have to see what OP thinks.

vs97 · Accepted Answer · 2019-08-24 18:16:09Z

1

You could possibly just not allow any space between the digit and the characters that follow:

\d+[^ ]?[g-k]

Notice, that [g-k] means that you accept a range of characters from g to k, i.e. examples like 900h, 900ij will match. If you do not want that and only want k and g characters to match, you can simply do:

\d+[^ ]?[gk]

If you are specifically interested in the kg order, you can simply do:

\d+[^ ]k?g --> this is same as Code Maniac answer \d+k?g

Obviously also notice the ignore case flag i - if you do not have that set, you will need to add upper-case letters to your regex as well.

answered Aug 24, 2019 at 18:16

vs97

5,8303 gold badges32 silver badges43 bronze badges

Collectives™ on Stack Overflow

Regex, match numbers and then a range of characters

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related