Split a string at every occurrence of a date format yyyy-mm-dd

Question

I'm trying to split a string at every occurrence of a specific pattern. I have a string like this one:

91.240.109.42FrancePrestashop PI block
2021-06-02213.186.52.66FrancePrestaShop
2012-06-29

And I want to split the string at every occurrence of the date format yyyy-mm-dd mantaining the date in the splitted array, so the result I want to obtain is this one:

[91.240.109.42FrancePrestashop PI block 2021-06-02,213.186.52.66FrancePrestaShop 2012-06-29]

I have tried to split based on the date format but it does not work:

var splitted_string= result.split(/^\d{4}-\d{2}-\d{2}$/)

First of all, don't use `^` and `$` anchors unless you're trying to match the entire string. Second, you probably should use a Lookahead if you want to keep the delimiter. — 41686d6564 stands w. Palestine, Jun 03 '21 at 10:19
Does this answer your question? [Javascript and regex: split string and keep the separator](https://stackoverflow.com/questions/12001953/javascript-and-regex-split-string-and-keep-the-separator) — 41686d6564 stands w. Palestine, Jun 03 '21 at 10:21
Isn't the expected result `["91.240.109.42FrancePrestashop PI block 2021-06-02", "213.186.52.66FrancePrestaShop 2012-06-29"]`? — Wiktor Stribiżew, Jun 03 '21 at 10:23

score 1 · Accepted Answer · answered Jun 03 '21 at 10:19

Use match here, with the following regex pattern:

[\s\S]+?(?:\d{4}-\d{2}-\d{2}|$)

This will match all content up until the first date, repeteadly through the text.

var input = `91.240.109.42FrancePrestashop PI block
2021-06-02213.186.52.66FrancePrestaShop
2012-06-29`
var matches = input.match(/[\s\S]+?(?:\d{4}-\d{2}-\d{2}|$)/g);
console.log(matches);

Note that I use logic such that should the input not end in a date, the final split value would still be included.

score 1 · Answer 2 · answered Jun 03 '21 at 10:28

You can use

const text = `91.240.109.42FrancePrestashop PI block
2021-06-02213.186.52.66FrancePrestaShop
2012-06-29`;
console.log( text.split(/(?<=\d{4}-\d{2}-\d{2})/).map(x=>x.replaceAll("\n"," ")) )

The (?<=\d{4}-\d{2}-\d{2}) pattern is a positive lookbehind that matches a location that is immediately preceded with four digits, -, two digits, - and two digits.

See this regex demo.

With .map(x=>x.replaceAll("\n"," "), you replace each LF Char with a space.

Split a string at every occurrence of a date format yyyy-mm-dd

2 Answers2