Comma delimited string to array using regular expressions

Question

I have a string: strString = first,last,,4443334444

I want to use regular expression to split this string into an array.

I'm using this regular expression [\""].+?[\""]|[^,]+ but it is ignoring the space after the word last.

So, my array is looking something like this:

        [0] => first
        [1] => last
        [2] => 4443334444

instead of:

        [0] => first
        [1] => last
        [2] => 
        [3] => 4443334444

I would like to keep the space.

Any help would be appreciated.

@evolutionxbox: Because it will split `"Text, text"` incorrectly. @TheGooose, try [`"[^"\\]*(?:\\.[^"\\]*)*"|[^,]+|(?<=^|,)(?=$|,)`](https://regex101.com/r/oI6kY9/1). — Wiktor Stribiżew, Jun 22 '16 at 23:20
Possible duplicate of [Regex to split a CSV](http://stackoverflow.com/questions/18144431/regex-to-split-a-csv) — Ro Yo Mi, Jun 22 '16 at 23:42
@Wiktor Thank you for your response, it had the desired output and takes into account qualified text with quotes worked good for my use case. I really appreciate all the responses and this awesome community. — The Goose, Jun 23 '16 at 15:28
I posted an answer. If you let know what language it is for, I could share a demo. Not sure you need it though :) — Wiktor Stribiżew, Jun 23 '16 at 20:24
If [my answer](https://stackoverflow.com/a/38001150/3832970) worked for you, please consider accepting. — Wiktor Stribiżew, Feb 24 '19 at 00:37

score 2 · Answer 1 · answered Jun 23 '16 at 20:23

You may use

"[^"\\]*(?:\\.[^"\\]*)*"|[^,]+|(?<=^|,)(?=$|,)‌

The expression consists of

"[^"\\]*(?:\\.[^"\\]*)*" - a double quoted string literal with escape sequence support
| - or
[^,]+ - 1 or more characters other than ,
| - or
(?<=^|,)(?=$|,)‌ - any empty string that is either between commas, or between the start/end of string and a comma.

score 0 · Answer 2 · answered Jun 22 '16 at 22:40

A couple of issues with your expression.

First [\""] is redundant, use ["] or better " (without the character class) instead.
Second, your actual problem is due to the + operator which requires at least one character (but there's none between the commas, thus disallowing empty fields).
Third, this is probably some CSV output, so why not use explode() or similar functions?

If you insist on using a regular expression, you might get along with:

".*?"|[^,]*

score 0 · Answer 3 · edited Jun 20 '20 at 09:12

Not sure if there's a way to get the element between the two commas, since there's no regex expression for it. The best I could come up with is:

str.match(/(?:[^,]+)|,,/g)

=> ["first", "last", ",,", "4443334444"]

But you'll need to translate the ",," into an empty string.

3 Answers3