comb, words, lines, split

Four methods that cut a string into a list of pieces, and how to pick the right one.

All four members of this family take one string and give you back a list of smaller strings. They differ in where they cut, and in what they do with the parts between the cuts.

The family

.comb — keeps what you want

Without an argument, .comb gives you every character on its own.

say 'Riga'.comb;

(R i g a)

With a pattern, it keeps only the pieces that match the pattern and throws the rest away. Here the pattern \d+ means “one or more digits”.

say '2026-10-22'.comb(/\d+/);
say 'Platform 9, train 3014 to Utrecht'.comb(/\d+/);

(2026 10 22)
(9 3014)

.words — cuts at spaces

.words cuts wherever there is whitespace: spaces, tabs or line breaks. It does not matter how many there are in a row.

say 'bread   butter  cheese'.words;
say '  one more time  '.words;

(bread butter cheese)
(one more time)

.lines — cuts at line breaks

.lines gives you one string per line, without the line break at the end of each.

my $list = "milk\nbread\neggs\n";
say $list.lines;
say $list.lines.elems;

(milk bread eggs)
3

The line break after eggs does not make a fourth, empty line.

.split — cuts where you say

.split cuts at the separator you give it, and keeps everything between the separators, even when there is nothing there.

say 'Amsterdam,Rotterdam,,Utrecht'.split(',');
say 'Amsterdam,Rotterdam,,Utrecht'.split(',').elems;

(Amsterdam Rotterdam  Utrecht)
4

Between the two commas there is an empty string. It shows up as the double space in the output, and it counts as an element.

Side by side

Method	Cuts at	Gives you	Empty pieces
.comb	—	the characters, or the matches of a pattern	never
.words	any whitespace	the words	never
.lines	line breaks	the lines	only empty lines in the middle
.split	the separator you give	everything between separators	kept

A way to remember them: .comb describes what you keep, .split describes what you throw away, and .words and .lines already know both.

Which one?

Which method would you use for each task?

1. Get the four digits of the year 2026 one by one.
2. Read the fields of the line Anna;;Leiden;31, where the second field is empty on purpose.
3. Get the words of a sentence that someone typed with two spaces after each full stop.
4. Get all the numbers from 3 apples and 12 pears.

Answers

1. .comb: '2026'.comb gives (2 0 2 6).
2. .split(';'), because it keeps the empty field, so the city is always the third element.
3. .words. .split(' ') would give you empty strings for the double spaces.
4. .comb(/\d+/) gives (3 12).