Simple regex extraction into multiple groups-CodePudding

Given this text

unit: 100 street: 200 city: 300

How do I write a regex that will give this output as different groups in JS. I also need to mention that the text may not contain street or city. It could just be unit: 100.

group[1] - 100
group[2] - 200
group[3] - 300

Where I'm at so far - unit:\s(.*?)\s(?:.*|$)

Not sure how to proceed further and get all 3 groups in one regex!

CodePudding user response：

We can use match() here:

var input = "unit: 100 street: 200 city: 300";
var matches = input.match(/(?<=: ).*?(?=\s*\w :|$)/g);
console.log(matches);

CodePudding user response：

You may do this using split as well:

const s = 'unit: 100 street: 200 city: 300';

var arr = s.split(/\s*\w :\s*/).filter(Boolean);

console.log( arr );

//=> ["100", "200", "300"]

Here \s*\w :\s* matches 0 or more spaces, followed by 1 word characters then : and 0 or more whitespaces.

Note the filter(Boolean) is just used to remove empty elements from resulting array.

CodePudding user response：

const rgx = /\D*(\d)(\d) /g

Regex101

Segment	Description
\D*	Zero or more non-digits
(\d)	First capture group of a digit
(\d)	Second capture group of one or more digits
g	`g`lobal flag

.replace() with

"group[$1] - $1$2$2\n"

Segment	Description
group[$1]	Replace with literal: `group[`, then the first capture group of `(\d)`, and then a literal: `]`
-	Then a space, a literal hyphen `-`, and a space
$1$2$2\n	Next, the first capture group again: `(\d)`, then the second capture group: `(\d)` twice, and finally a newline

Example A

const str = `unit: 100 street: 200 city: 300`;
const rgx = /\D*(\d)(\d) /g;

const res = str.replace(rgx, "group[$1] - $1$2$2\n");
console.log(res);

Note: The following comment was not considered in Example A:

It need not be numbers, could be any text."

The question should have this criteria added and an appropriate example:

'unit: 100 street: Main city: Springfield'

Because of this part: group[?], more than one method is needed. See Example B for a solution.

Example B

const str = 'unit: 100 street: Main city: Springfield';
const rgx = /\b(\w :) ([\w] )/g;

const res = str.replace(rgx, "$2")
            .split(' ')
            .map((s, i) => 
              "group[" (i   1) "] - " s).join('\n');

console.log(res);