Regular expression \S* causes "JavaScript heap out of memory"

Question

I'm trying to select all non whitespace characters. But regular expression \S* or [^\s]* failing with "JavaScript heap out of memory" error for any string.

I tried it with node and directly on browser console. However when I tried it with an online regex tester then it worked fine.

var validAttrStrRegxp = new RegExp("\\S*", "g");
getAllMatches("any string",validAttrStrRegxp);

var getAllMatches = function(string, regex) {
  var matches = [];
  var match = regex.exec(string);
  while (match) {
    var allmatches = [];
    for (var index = 0; index < match.length; index++) {
        allmatches.push(match[index]);
    }
    matches.push(allmatches);
    match = regex.exec(string);
  }
  return matches;
};

not sure but can it be because JS treats an empty string as whitespace char `/\S/.test(""); //true` — Amit Kumar Gupta, Feb 03 '18 at 06:35
@user202729 No, see [this](https://stackoverflow.com/questions/11477415/why-does-javascripts-regex-exec-not-always-return-the-same-value). — user202729, Feb 03 '18 at 06:43
Have you tried to debug it? (e.g, add a `console.log(match)` at each iteration to see what the regex matches)? — user202729, Feb 03 '18 at 06:47
@user202729 sorry buddy but I'm confused with your comments. Please check [this](https://stackoverflow.com/questions/6323417/how-do-i-retrieve-all-matches-for-a-regular-expression-in-javascript) link regarding loop. You can change the re to `\\S+` and it'll not stuck in infinite loop. The link you commented, was it for me or for yourself? — Amit Kumar Gupta, Feb 03 '18 at 06:58
I would love to know the reason of down vote. It'll help me to improve the question quality in future. — Amit Kumar Gupta, Feb 03 '18 at 07:06
"Have you tried to debug it?" - well, that. You solved your own question anyway, so no problem. — user202729, Feb 03 '18 at 07:09

score 2 · Accepted Answer · answered Feb 03 '18 at 07:05

2

I got the reason. As * means 0 or many. The RE I specified also means to match for empty pattern. Hence the issue is not being caused with \\S+.

answered Feb 03 '18 at 07:05

Amit Kumar Gupta

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Regular expression \S* causes "JavaScript heap out of memory"

1 Answers1