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Replacement Strings Reference: Conditionals

FeatureSyntaxDescriptionExample JGsoft .NET Java Perl PCRE2 PHP Delphi R JavaScript VBScript XRegExp Python Ruby std::regex Boost Tcl ARE Oracle XPath
Conditional ?1yes:no through ?99yes:no Conditional referencing a numbered capturing group. Inserts the "yes" part if the group participated or the "no" part if it didn't. Replacing all matches of (y)?|n in yyn! with ?1yes:no yields yesyesno! nonononononononononononononoallnonono
Conditional (?1yes:no) through (?99yes:no) Conditional referencing a numbered capturing group. Inserts the "yes" part if the group participated or the "no" part if it didn't. Replacing all matches of (y)?|n in yyn! with (?1yes:no) yields yesyesno! V2nononononononononononononoallnonono
Conditional (?10yes:no) through (?99yes:no) When there are fewer capturing groups than the 2-digit number, treat this as a single-digit conditional with the "yes" part starting with a literal number instead of as an invalid conditional. Replacing all matches of (y)?|n in yyn! with (?19yes:no) yields 9yes9yesno! V2n/an/an/an/an/an/an/an/an/an/an/an/an/anon/an/an/a
Conditional ?{1}yes:no through ?{99}yes:no Conditional referencing a numbered capturing group. Inserts the "yes" part if the group participated or the "no" part if it didn't. Replacing all matches of (y)?|n in yyn! with ?{1}yes:no yields yesyesno! nonononononononononononononoall
1.42–1.64
nonono
Conditional (?{1}yes:no) through (?{99}yes:no) Conditional referencing a numbered capturing group. Inserts the "yes" part if the group participated or the "no" part if it didn't. Replacing all matches of (y)?|n in yyn! with (?{1}yes:no) yields yesyesno! V2nononononononononononononoall
1.42–1.64
nonono
Conditional ${1:+yes:no} through ${99:+yes:no} Conditional referencing a numbered capturing group. Inserts the "yes" part if the group participated or the "no" part if it didn't. Replacing all matches of (y)?|n in yyn! with ${1:+yes:no} yields yesyesno! V2nononoextendednonononononononononononono
Conditional ${1:-no} through ${99:-no} Conditional referencing a numbered capturing group. Inserts the text captured by the group if it participated or the contents of the conditional if it didn't. Replacing all matches of (y)?|n in yyn! with ${1:-no} yields yyno! V2nononoextendednonononononononononononono
Conditional Any numbered conditional A conditional that references the number of a capturing group that does not exists acts as a conditional to a group that never participates. Replacing all matches of (y)?|n in yyn! with (?9yes:no) yields nonono! V2 errorn/an/an/aextended errorn/an/an/an/an/an/an/an/an/aalln/an/an/a
Conditional $?{name}yes:no Conditional referencing a named capturing group. Inserts the "yes" part if the group participated or the "no" part if it didn't. Replacing all matches of (?'one'y)?|n in yyn! with ?{one}yes:no yields yesyesno! nonononononononononononononoall
1.42–1.64
nonono
Conditional (?{name}yes:no) Conditional referencing a named capturing group. Inserts the "yes" part if the group participated or the "no" part if it didn't. Replacing all matches of (?'one'y)?|n in yyn! with (?{one}yes:no) yields yesyesno! V2nononononononononononononoall
1.42–1.64
nonono
Conditional ${name:+yes:no} Conditional referencing a named capturing group. Inserts the "yes" part if the group participated or the "no" part if it didn't. Replacing all matches of (?'one'y)?|n in yyn! with ${one:+yes:no} yields yesyesno! V2nononoextendednonononononononononononono
Conditional ${name:-no} Conditional referencing a named capturing group. Inserts the text captured by the group if it participated or the contents of the conditional if it didn't. Replacing all matches of (?'one'y)?|n in yyn! with ${one:-no} yields yyno! V2nononoextendednonononononononononononono
Conditional Any named conditional A conditional that references the name of a capturing group that does not exists is treated as literal text. Replacing all matches of (y)?|n in yn! with (?{name}yes:no) yields ?{name}yes:no?{name}yes:no! V2 errorn/an/an/aextended errorn/an/an/an/an/an/an/an/an/aall
1.42–1.64
n/an/an/a
FeatureSyntaxDescriptionExample JGsoft .NET Java Perl PCRE2 PHP Delphi R JavaScript VBScript XRegExp Python Ruby std::regex Boost Tcl ARE Oracle XPath

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Replacement Reference
Introduction
Table of Contents
Characters
Matched Text & Backreferences
Context & Case Conversion
Conditionals
Regular Expressions Reference
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