CODEWITHSUNDEEP
rregex
andrew
andrew

Reputation: 49

Regular expression to extract characters between a space and a string

I have a string like this:

"Samsung LA32D450 LCD Television 32inch Black"

I need to extract the size of the TV so I need to extract all characters between 'inch' and the preceeding whitespace. In this case I would need the expression to return 32

The regular expression needs to be able to deal with decimal points. For example I would need 32.5 from this string:

"Samsung LA32D450 LCD Television 32.5inch Black"

Upvotes: 0

Views: 1074

Answers (3)

Ekrem Demirhan
Ekrem Demirhan

Reputation: 204

(?<=\s)(\d+\.?\d*)(?=inch)

It matches the part that comes before inch. \d+ part matches decimal part and then it matches for an optional .. After that it looks for fractional part with \d*.

After realizing that it accepts numbers like .6, I make a quick edit. It looks for space character before digit part.

https://regex101.com/r/tionn9/2

Upvotes: 0

jrook
jrook

Reputation: 3519

You need to match numbers (possibly including a dot) followed by the word inch.

You can use lookaheads to get what you want:

[\d.]+(?=inch)

This will match a combination of numbers an dots repeated 1 or more times followed by the word inch.

You can of course, get more precise by specifying the format of the numbers.

EDIT:

Getting more precise about the number format can introduce extra complexities. I came up with this regex to match only either 2-3 digits followed by "inch" (23inch) or just 2-3 digits followed by a dot followed by one digit followed by "inch"(23.5inch). It uses both lookaheads and negative lookbehinds so your regex engine should support these constructs:

\b(?<![.\d])([1-9][0-9]{1,2}\.[1-9]|[1-9][0-9]{1,2})(?=inch)

Regex 101

Upvotes: 2

theLudo
theLudo

Reputation: 137

Try the following:

library(stringr)
a <- "Samsung LA32D450 LCD Television 32.1inch Black"
str_extract(a, "[:graph:]*(?=inch)")

[:graph:] matches either letters, numbers or punctuation, but not white-space.

?=inch matches everything followed by "inch".

Good luck,

Ludo

Upvotes: 0

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