Convert self
to UTF-16
Convert self
to UTF-32
Convert self
to locale encoding
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
.
Iterates through successive values, starting at str and ending at other_str inclusive, passing each value in turn to the block. The String#succ
method is used to generate each value. If optional second argument exclusive is omitted or is false, the last value will be included; otherwise it will be excluded.
If no block is given, an enumerator is returned instead.
"a8".upto("b6") {|s| print s, ' ' } for s in "a8".."b6" print s, ' ' end
produces:
a8 a9 b0 b1 b2 b3 b4 b5 b6 a8 a9 b0 b1 b2 b3 b4 b5 b6
If str and other_str contains only ascii numeric characters, both are recognized as decimal numbers. In addition, the width of string (e.g. leading zeros) is handled appropriately.
"9".upto("11").to_a #=> ["9", "10", "11"] "25".upto("5").to_a #=> [] "07".upto("11").to_a #=> ["07", "08", "09", "10", "11"]
Replaces the contents and taintedness of str with the corresponding values in other_str.
s = "hello" #=> "hello" s.replace "world" #=> "world"
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 a new string with the characters from str in reverse order.
"stressed".reverse #=> "desserts"
Reverses str in place.
Prepend—Prepend the given strings to str.
a = "!" a.prepend("hello ", "world") #=> "hello world!" a #=> "hello world!"
See also String#concat
.
If integer is greater than the length of str, returns a new String
of length integer with str left justified and padded with padstr; otherwise, returns str.
"hello".ljust(4) #=> "hello" "hello".ljust(20) #=> "hello " "hello".ljust(20, '1234') #=> "hello123412341234123"
If integer is greater than the length of str, returns a new String
of length integer with str right justified and padded with padstr; otherwise, returns str.
"hello".rjust(4) #=> "hello" "hello".rjust(20) #=> " hello" "hello".rjust(20, '1234') #=> "123412341234123hello"
Returns a copy of the receiver with leading and trailing whitespace removed.
Whitespace is defined as any of the following characters: null, horizontal tab, line feed, vertical tab, form feed, carriage return, space.
" hello ".strip #=> "hello" "\tgoodbye\r\n".strip #=> "goodbye" "\x00\t\n\v\f\r ".strip #=> "" "hello".strip #=> "hello"
Returns a copy of the receiver with leading whitespace removed. See also String#rstrip
and String#strip
.
Refer to String#strip
for the definition of whitespace.
" hello ".lstrip #=> "hello " "hello".lstrip #=> "hello"
Returns a copy of the receiver with trailing whitespace removed. See also String#lstrip
and String#strip
.
Refer to String#strip
for the definition of whitespace.
" hello ".rstrip #=> " hello" "hello".rstrip #=> "hello"
Removes leading and trailing whitespace from the receiver. Returns the altered receiver, or nil
if there was no change.
Refer to String#strip
for the definition of whitespace.
" hello ".strip! #=> "hello" "hello".strip! #=> nil
Removes leading whitespace from the receiver. Returns the altered receiver, or nil
if no change was made. See also String#rstrip!
and String#strip!
.
Refer to String#strip
for the definition of whitespace.
" hello ".lstrip! #=> "hello " "hello ".lstrip! #=> nil "hello".lstrip! #=> nil
Removes trailing whitespace from the receiver. Returns the altered receiver, or nil
if no change was made. See also String#lstrip!
and String#strip!
.
Refer to String#strip
for the definition of whitespace.
" hello ".rstrip! #=> " hello" " hello".rstrip! #=> nil "hello".rstrip! #=> nil
Returns the value of float
as a BigDecimal
. The precision
parameter is used to determine the number of significant digits for the result (the default is Float::DIG
).
require 'bigdecimal' require 'bigdecimal/util' 0.5.to_d # => 0.5e0 1.234.to_d(2) # => 0.12e1
See also BigDecimal::new
.
Returns a string containing a representation of self
. As well as a fixed or exponential form of the float
, the call may return NaN
, Infinity
, and -Infinity
.
Since float
is already a Float
, returns self
.