Master programming syntax, solve interactive challenges & run live code in Syntaxis Explore Arena →
menu_book Course Curriculum (Perl) expand_more
Foundations
Strict and warnings Scalar variables Array variables Hash variables Numeric context String context Undef Defined
Strings and Regex
Double quoted interpolation Single quoted strings Quoting operators Regex match Regex substitution Capture groups Named captures Transliteration
Control Flow
If elsif Unless While Until For loop Foreach Next last redo Given when concept
Lists and Arrays
List context Array slices Push pop Shift unshift Splice Map Grep Sort
Hashes and References
Hash literals Exists Delete Keys values Scalar references Array references Hash references Dereferencing
Subroutines
Sub definitions Argument list @_ Signatures Return values Lexical closures State variables Prototypes concept Wantarray
Modules and OO
Packages Use require Exporter Bless Methods Inheritance @ISA SUPER Moose concept
File and I/O
Open read Open write Three-arg open Diamond operator Filehandles Local $/ slurp File::Spec Directory handles
Errors and Processes
Die Warn Eval exception handling $@ error variable System Qx command capture Fork concept Signals %SIG
Advanced Perl
Autovivification Local vs my Our variables Tie concept Overload concept END blocks DATA handle Getopt::Long
Perl / Control Flow

Until

Learn until in Perl through a focused explanation, a dedicated topic-specific example, an engineering boundary, and a mastery check.

10 min read • Beginner

until is an atomic Perl topic inside Control Flow. The example uses the named construct directly so you can see its syntax, data flow, and observable behavior.

Read the code by locating the exact feature named until, then trace the value before and after that feature runs. This lesson is intentionally isolated from neighboring topics: changing identifiers alone would not reproduce the same behavior because the construct itself is different.

Topic-specific example

perl-0020-eaa23ee843.pl
perl Try It Live 
my $n=0; until($n==3){$n++} print "$n\n";
Edge case / engineering note

For until, test the boundary that makes the feature meaningful: invalid input, an empty value, a missing branch, lifecycle/cleanup, or a type/runtime constraint. Do not infer correctness only from the happy path.

Content source & attribution
Original Syntaxis Content · Original Syntaxis Content

Lesson quizzes

Until Mastery Check →
← PREVIOUS
While
NEXT →
For loop