CODEWITHSUNDEEP
regex
doublemc
doublemc

Reputation: 3311

Regex last occurence of digit before some string

I'm trying to create regex to retrieve last number if there was a number or any number if there wasn't any from a string. Examples:

 6 łyżek stopionego masła -> 6
5 łyżek blabla, 6 łyżek masła -> 6
5 łyżek mąki lub masła -> 5

I'm matching only on masła (changing variable) so it has to be included in regex

EDIT: I cannot explain what I actually need: Here is regex101 example: https://regex101.com/r/pEeRk3/1

EDIT2: Emma's solution works great, but I would need to parse decimals and 2multiple digit numbers as well, meaning that those would match as well: https://regex101.com/r/pEeRk3/3 - I added examples with answers in the link

Upvotes: 1

Views: 55

Answers (2)

The fourth bird
The fourth bird

Reputation: 163632

If you want to match the last occurence of a digit with a decimal and you word has to follow this value, you might use lookarounds:

(?<!\S)\d+(?:\.\d+)?(?!\S)(?!.*\d)(?=.*masła)
  • (?<!\S)\d+(?:\.\d+)?(?!\S) Match 1+ digits with an optional past to match a dot and 1+ digits
  • (?!.*\d) assert that there are no more digits following
  • (?=.*masła) Assert what is on the right is your word

Regex demo

Or you might use a capturing group:

(?<!\S)(\d+(?:\.\d+)?)[^\d\n]* masła(?!\S)[^\d\n]*$

Regex demo

Upvotes: 2

Emma
Emma

Reputation: 27743

This expression might simply suffice: 

.*([0-9])

if we are interested in one digit only, or

.*([0-9]+)

if multiple digits might be desired.

Demo 1

If those strings with masła are desired, we can expand our expression to:

(?=.*masła).*([0-9])

Demo 2

If we would not be validating our numbers and our number would be valid, with commas or dots, then this expression might likely return our desired output:

(?=.*masła)([0-9,.]+)(\D*)$

Demo 3

Upvotes: 1

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