如何使用正则表达式查找以下模式？

Question

I have an array of strings like so:

["Author Name, (p. 123). (2019). Company.", "Author Name, (p. 321). (2021). Company."]

How can I return the page numbers that start with and contain the pattern (p. ?

So far I have tried /\(([^)\)]+)\)/ however it returns everything with parentheses. I only want the page numbers with parentheses.

Answer 1

You can match the p. before the capture group and capture the numbers. You don't have to escape the parenthesis in the character class, so you can remove \) and leave just )

\(p\.\s*([^)]+)\)

See a regex demo .

 const regex = /\(p\.\s*([^)]+)\)/g; [ "Author Name, (p. 123). (2019). Company.", "Author Name, (p. 321). (2021). Company." ].forEach(s => { Array.from(s.matchAll(regex), m => console.log(m[1])) });

Answer 2

I'd capture digits (you need (ps) ?), case-insensitive (what about (P.12) ?):

/\(p\.\s*(\d+)\)/ig

Code

 const regex = /\(p\.\s*(\d+)\)/gi const string = "Author Name, (p. 123). (2019). Company." console.log(string.match(regex).map(x => x.replace(/\D+/g, '')))

EXPLANATION

NODE                     EXPLANATION
--------------------------------------------------------------------------------
  \(                       '('
--------------------------------------------------------------------------------
  p                        'p'
--------------------------------------------------------------------------------
  \.                       '.'
--------------------------------------------------------------------------------
  \s*                      whitespace (\n, \r, \t, \f, and " ") (0 or
                           more times (matching the most amount
                           possible))
--------------------------------------------------------------------------------
  (                        group and capture to \1:
--------------------------------------------------------------------------------
    \d+                      digits (0-9) (1 or more times (matching
                             the most amount possible))
--------------------------------------------------------------------------------
  )                        end of \1
--------------------------------------------------------------------------------
  \)                       ')'

See regex proof .