Preview Ruby 4.1 is a preview. It can change before the final release. Switch to Ruby 4.0 →
instance method
String#downcase
() -> ::String
(:ascii | :fold | :lithuanian | :turkic) -> ::String
(:lithuanian, :turkic) -> ::String
(:turkic, :lithuanian) -> ::String
downcase(mapping = :ascii) → new_string
string.c
View on GitHub ↗
static VALUE
rb_str_downcase(int argc, VALUE *argv, VALUE str)
{
rb_encoding *enc;
OnigCaseFoldType flags = ONIGENC_CASE_DOWNCASE;
VALUE ret;
flags = check_case_options(argc, argv, flags);
enc = str_true_enc(str);
if (case_option_single_p(flags, enc, str)) {
ret = rb_str_new(RSTRING_PTR(str), RSTRING_LEN(str));
str_enc_copy_direct(ret, str);
downcase_single(ret);
}
else if (flags&ONIGENC_CASE_ASCII_ONLY) {
ret = rb_str_new(0, RSTRING_LEN(str));
rb_str_ascii_casemap(str, ret, &flags, enc);
}
else {
ret = rb_str_casemap(str, &flags, enc);
}
return ret;
}
Returns a new string containing the downcased characters in self:
Example
'HELLO'.downcase # => "hello" 'STRAẞE'.downcase # => "straße" 'ПРИВЕТ'.downcase # => "привет" 'RubyGems.org'.downcase # => "rubygems.org"
Some characters (and some character sets) do not have upcase and downcase versions; see Case Mapping:
Example
s = '1, 2, 3, ...' s.downcase == s # => true s = 'こんにちは' s.downcase == s # => true
The casing is affected by the given mapping, which may be :ascii, :fold, or :turkic; see Case Mappings.
Related: see Converting to New String.
Ruby version changes
-
3.0
-
The following methods now return or yield
Stringinstances instead of subclass instances when called on subclass instances: [Bug #10845]
-