instance method
String#capitalize
() -> ::String
(:ascii | :lithuanian | :turkic) -> ::String
(:lithuanian, :turkic) -> ::String
(:turkic, :lithuanian) -> ::String
capitalize(mapping = :ascii) → new_string
string.c
View on GitHub ↗
static VALUE
rb_str_capitalize(int argc, VALUE *argv, VALUE str)
{
rb_encoding *enc;
OnigCaseFoldType flags = ONIGENC_CASE_UPCASE | ONIGENC_CASE_TITLECASE;
VALUE ret;
flags = check_case_options(argc, argv, flags);
enc = str_true_enc(str);
if (RSTRING_LEN(str) == 0 || !RSTRING_PTR(str)) return str;
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 string containing the characters in self, each with possibly changed case:
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The first character made uppercase.
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All other characters are made lowercase.
Examples:
Example
'hello'.capitalize # => "Hello" 'HELLO'.capitalize # => "Hello" 'straße'.capitalize # => "Straße" # Lowercase 'ß' not changed. 'STRAẞE'.capitalize # => "Straße" # Uppercase 'ẞ' downcased to 'ß'. 'привет'.capitalize # => "Привет" 'ПРИВЕТ'.capitalize # => "Привет"
Some characters (and some character sets) do not have upcase and downcase versions; see Case Mapping:
Example
s = '1, 2, 3, ...' s.capitalize == s # => true s = 'こんにちは' s.capitalize == 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
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3.0
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The following methods now return or yield
Stringinstances instead of subclass instances when called on subclass instances: [Bug #10845]
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