Splitting a string by space, ignoring spaces in nested strings

Question

Currently, I can split a string like this:

"1 2 3".split(' ') // [ "1", "2", "3" ]
"1 2 3 'word'".split(' ') // [ "1", "2", "3", "'word'" ]

Is there a way to avoid splitting on a space within a nested string?

For example:

"1 2 3 'word one'".split(' ') // want output of [ "1", "2", "3", "'word one'" ]
"1 2 3 \"word one\"".split(' ') // want output of [ "1", "2", "3", "\"word one\"" ]

I want output of [ "1", "2", "3", "'word one'" ] instead of [ "1", "2", "3", "'word", "one'" ] (i.e. I want to ignore spaces if they are in strings).

Answer 1

One approach can be to use match with a regex that accounts for the spaces inside quotes:

var s = "1 2 3 \"word one\" one \"two\" 'hello world'";
console.log(s.match(/'[^']+'|"[^"]+"|\w+/g));

Edit: See Certain Performance's answer for a better regex.

• CertainPerformance: This will match too much if the string contains more quote characters later, eg 1 "2" "3". \w also assumes word characters, which may well not be the case.

Answer 2

To correctly match strings containing additional quote characters, when matching substrings in quotes, lazy-repeat the . with .+?, otherwise strings such as

1 "2" "3"

won't match properly. Also, unless you can count on all matches containing just word characters, probably better to use \S (which will match anything but whitespace characters):

var s = `1 "2" "3" foo'bar`
console.log(s.match(/'.+?'|".+?"|\S+/g));

Or, to be slightly more efficient, rather than lazy repetition, use negative character classes instead:

var s = `1 "2" "3" foo'bar`
console.log(s.match(/'[^']+'|"[^"]+"|\S+/g));

Answer 3

Walk through the string and keep a Boolean flag for if you're within quotes.

if(string[i] == ' ' && !insideQuotes) //split