在逗号或空格上匹配正则表达式，但不能两者都匹配

Question

I need to have a regular expression that replaces commas and spaces with a comma and a space, but leaves it alone if it's already a comma and a space in sequence.

Example:

44,55 90 should turn into 44, 55, 90

but, 44, 55, 90 when entered again should remain the same.

I initially tried /[\\s,]/g but it of course replaces any comma or space with both a comma and space, so 44, 55, 90 became 44, , 55, , 90

Answer 1

The answer is very simple / ,?|,/g
Or if you want to remove any amount of white space before comma / *,?| /g / *,?| /g
Or if you want go crazy go with this /\\s*,\\s*|\\s+/g this will replace any extra spacing before , and after it and do all good stuf as erlier.

Answer 2

This will work for the test string, assuming you're looking to fix strings with digits, commas and spaces, and not other combinations of characters.

Search for this:

\\d(,)\\d|\\d([ ]{1,},[ ]{0,})\\d|\\d([ ]{1,})\\d

Replace capture group 1 with comma , and a space, .

That should handle any real or potential white space with quantifiers checking for multiple whitespaces.

Test string with 6 matches :

44,55 90 ,44 , 55 , 90 , 1234 ,

Answer 3

You could go the other way and replace everything that is not digits with anything you want, using a negated character class:

'999 123,098b7b7b7b7b,,,123^&*()43'.replace(/[^\d]+/g,', ');
//"999, 123, 098, 7, 7, 7, 7, 123, 43"