The first form transcodes the contents of str from str.encoding to encoding. The second form transcodes the contents of str from src_encoding to dst_encoding. The options keyword arguments give details for conversion. See String#encode for details. Returns the string even if no changes were made.
Changes the encoding to encoding and returns self.
Returns true for a string which is encoded correctly.
"\xc2\xa1".force_encoding("UTF-8").valid_encoding? #=> true "\xc2".force_encoding("UTF-8").valid_encoding? #=> false "\x80".force_encoding("UTF-8").valid_encoding? #=> false
Processes a copy of str as described under String#tr, then removes duplicate characters in regions that were affected by the translation.
"hello".tr_s('l', 'r') #=> "hero" "hello".tr_s('el', '*') #=> "h*o" "hello".tr_s('el', 'hx') #=> "hhxo"
If object is a String object, returns object.
Otherwise if object responds to :to_str, calls object.to_str and returns the result.
Returns nil if object does not respond to :to_str
Raises an exception unless object.to_str returns a String object.
Replaces the contents of str with the corresponding values in other_str.
s = "hello" #=> "hello" s.replace "world" #=> "world"
Returns an array of grapheme clusters in str. This is a shorthand for str.each_grapheme_cluster.to_a.
If a block is given, which is a deprecated form, works the same as each_grapheme_cluster.
Returns true if str starts with one of the prefixes given. Each of the prefixes should be a String or a Regexp.
"hello".start_with?("hell") #=> true "hello".start_with?(/H/i) #=> true # returns true if one of the prefixes matches. "hello".start_with?("heaven", "hell") #=> true "hello".start_with?("heaven", "paradise") #=> false
Performs String#tr_s processing on str in place, returning str, or nil if no changes were made.
Splits str using the supplied parameter as the record separator ($/ by default), passing each substring in turn to the supplied block. If a zero-length record separator is supplied, the string is split into paragraphs delimited by multiple successive newlines.
If chomp is true, separator will be removed from the end of each line.
If no block is given, an enumerator is returned instead.
"hello\nworld".each_line {|s| p s} # prints: # "hello\n" # "world" "hello\nworld".each_line('l') {|s| p s} # prints: # "hel" # "l" # "o\nworl" # "d" "hello\n\n\nworld".each_line('') {|s| p s} # prints # "hello\n\n" # "world" "hello\nworld".each_line(chomp: true) {|s| p s} # prints: # "hello" # "world" "hello\nworld".each_line('l', chomp: true) {|s| p s} # prints: # "he" # "" # "o\nwor" # "d"
Passes the Integer ordinal of each character in str, also known as a codepoint when applied to Unicode strings to the given block. For encodings other than UTF-8/UTF-16(BE|LE)/UTF-32(BE|LE), values are directly derived from the binary representation of each character.
If no block is given, an enumerator is returned instead.
"hello\u0639".each_codepoint {|c| print c, ' ' }
produces:
104 101 108 108 111 1593
Returns a complex which denotes the string form. The parser ignores leading whitespaces and trailing garbage. Any digit sequences can be separated by an underscore. Returns zero for null or garbage string.
'9'.to_c #=> (9+0i) '2.5'.to_c #=> (2.5+0i) '2.5/1'.to_c #=> ((5/2)+0i) '-3/2'.to_c #=> ((-3/2)+0i) '-i'.to_c #=> (0-1i) '45i'.to_c #=> (0+45i) '3-4i'.to_c #=> (3-4i) '-4e2-4e-2i'.to_c #=> (-400.0-0.04i) '-0.0-0.0i'.to_c #=> (-0.0-0.0i) '1/2+3/4i'.to_c #=> ((1/2)+(3/4)*i) 'ruby'.to_c #=> (0+0i)
See Kernel.Complex.
Returns the result of interpreting leading characters in str as a BigDecimal.
require 'bigdecimal' require 'bigdecimal/util' "0.5".to_d # => 0.5e0 "123.45e1".to_d # => 0.12345e4 "45.67 degrees".to_d # => 0.4567e2
See also BigDecimal::new.
Returns the result of interpreting leading characters in str as a rational. Leading whitespace and extraneous characters past the end of a valid number are ignored. Digit sequences can be separated by an underscore. If there is not a valid number at the start of str, zero is returned. This method never raises an exception.
' 2 '.to_r #=> (2/1) '300/2'.to_r #=> (150/1) '-9.2'.to_r #=> (-46/5) '-9.2e2'.to_r #=> (-920/1) '1_234_567'.to_r #=> (1234567/1) '21 June 09'.to_r #=> (21/1) '21/06/09'.to_r #=> (7/2) 'BWV 1079'.to_r #=> (0/1)
NOTE: “0.3”.to_r isn’t the same as 0.3.to_r. The former is equivalent to “3/10”.to_r, but the latter isn’t so.
"0.3".to_r == 3/10r #=> true 0.3.to_r == 3/10r #=> false
See also Kernel#Rational.
Returns the result of interpreting leading characters in str as an integer base base (between 2 and 36). Extraneous characters past the end of a valid number are ignored. If there is not a valid number at the start of str, 0 is returned. This method never raises an exception when base is valid.
"12345".to_i #=> 12345 "99 red balloons".to_i #=> 99 "0a".to_i #=> 0 "0a".to_i(16) #=> 10 "hello".to_i #=> 0 "1100101".to_i(2) #=> 101 "1100101".to_i(8) #=> 294977 "1100101".to_i(10) #=> 1100101 "1100101".to_i(16) #=> 17826049
Returns the result of interpreting leading characters in str as a floating point number. Extraneous characters past the end of a valid number are ignored. If there is not a valid number at the start of str, 0.0 is returned. This method never raises an exception.
"123.45e1".to_f #=> 1234.5 "45.67 degrees".to_f #=> 45.67 "thx1138".to_f #=> 0.0
Returns the Symbol corresponding to str, creating the symbol if it did not previously exist. See Symbol#id2name.
"Koala".intern #=> :Koala s = 'cat'.to_sym #=> :cat s == :cat #=> true s = '@cat'.to_sym #=> :@cat s == :@cat #=> true
This can also be used to create symbols that cannot be represented using the :xxx notation.
'cat and dog'.to_sym #=> :"cat and dog"
Returns true if str ends with one of the suffixes given.
"hello".end_with?("ello") #=> true # returns true if one of the +suffixes+ matches. "hello".end_with?("heaven", "ello") #=> true "hello".end_with?("heaven", "paradise") #=> false
Returns a copy of str with leading prefix deleted.
"hello".delete_prefix("hel") #=> "lo" "hello".delete_prefix("llo") #=> "hello"
Returns a copy of str with trailing suffix deleted.
"hello".delete_suffix("llo") #=> "he" "hello".delete_suffix("hel") #=> "hello"
Deletes leading prefix from str, returning nil if no change was made.
"hello".delete_prefix!("hel") #=> "lo" "hello".delete_prefix!("llo") #=> nil
Deletes trailing suffix from str, returning nil if no change was made.
"hello".delete_suffix!("llo") #=> "he" "hello".delete_suffix!("hel") #=> nil
Passes each byte in str to the given block, or returns an enumerator if no block is given.
"hello".each_byte {|c| print c, ' ' }
produces:
104 101 108 108 111