In this example...

(5) (dogs)  (5 dogs)  (dogs 5)

I would like to only match to...

(5 dogs)  -or-  (dogs 5)

The numbers could be any number of digits, contain commas, decimal points, math operators, dollar signs, etc. The only thing I need to pay attention to is that there are both numbers and alpha characters present.

I started with this modification of an example provided by hrs using this for the RegEx...

\(((letter).*(number))\)|((number).*(letter))\)

to only capture this...

(number letter)  -or-  (letter number)

but not...

(number) (letter)

by modifying the expression to be...

\(((^[a-zA-Z]).*(^[0-9]))\)|((^[0-9]).*(^[a-zA-Z]))\)

...but obviously I don't know what I'm doing.

CodePudding user response：

You can use forward lookaheads to assert that there are both a number and a letter within each set of parentheses:

\((?=[^)]*\d)(?=[^)]*[a-z])[^)] \)

The two lookaheads assert that there are some number of non-closing parenthesis characters and then a digit (first lookahead (?=[^)]*\d)) or a letter (second lookahead (?=[^)]*[a-z])). The [^)] then matches the characters between the ( and ).

Demo on regex101

In Javascript:

const str = '(5) (dogs)  (5 dogs)  (dogs 5)'
const regex = /\((?=[^)]*\d)(?=[^)]*[a-z])[^)] \)/ig

console.log(str.match(regex))

CodePudding user response：

As an alternative with a single lookahead:

\((?=[^)a-z]*[a-z])[^\d)]*\d[^)]*\)

Explanation

• \( Match (
• (?= Positive lookahead
  • [^)a-z]*[a-z] Match any char except ) or a-z, then match a-z
• ) Close the lookahead
• [^\d)]*\d Match any char except a digit or ) and then match a digit
• [^)]* Match any char except )
• \) Match )

Regex demo

const s = '(5) (dogs)  (5 dogs)  (dogs 5)';
const regex = /\((?=[^)a-z]*[a-z])[^\d)]*\d[^)]*\)/ig;

console.log(s.match(regex));