Perl · Medium

Lesson 1 · On the house

map, grep, sort

List transforms; block forms; sort {$a<=>$b}.

Lesson 2

Named captures

(?<name>...), %+, $+{name}.

Lesson 3

Lookaround and qr

(?=) (?!) (?<=) (?<!); qr// compiled regex.

Lesson 4

s///e and expressions

Replacement as expression; safety note.

Lesson 5

Closures and state

Lexical capture in subs; state variables.

Lesson 6

eval and $@

Block eval for exceptions; localize $@; die/croak sketch.

Lesson 7

Exporter

@EXPORT / @EXPORT_OK; use Parent qw(...).

Lesson 8

wantarray and context

Subs that return differently in list vs scalar vs void.

Lesson 9

JSON::PP

encode_json / decode_json with hashrefs and arrayrefs.

Lesson 10

Medium capstone

map/grep, named captures or qr, closures, JSON::PP.