ruby/doc/string/swapcase.rdoc
2025-12-05 19:04:23 -08:00

33 lines
979 B
Plaintext

Returns a string containing the characters in +self+, with cases reversed:
- Each uppercase character is downcased.
- Each lowercase character is upcased.
Examples:
'Hello'.swapcase # => "hELLO"
'Straße'.swapcase # => "sTRASSE"
'Привет'.swapcase # => "пРИВЕТ"
'RubyGems.org'.swapcase # => "rUBYgEMS.ORG"
The sizes of +self+ and the upcased result may differ:
s = 'Straße'
s.size # => 6
s.swapcase # => "sTRASSE"
s.swapcase.size # => 7
Some characters (and some character sets) do not have upcase and downcase versions;
see {Case Mapping}[rdoc-ref:case_mapping.rdoc]:
s = '1, 2, 3, ...'
s.swapcase == s # => true
s = 'こんにちは'
s.swapcase == s # => true
The casing is affected by the given +mapping+,
which may be +:ascii+, +:fold+, or +:turkic+;
see {Case Mappings}[rdoc-ref:case_mapping.rdoc@Case+Mappings].
Related: see {Converting to New String}[rdoc-ref:String@Converting+to+New+String].