Returns the value as a rational. The optional argument eps is always ignored.
Returns the value as a rational if possible (the imaginary part should be exactly zero).
Complex(1.0/3, 0).rationalize #=> (1/3) Complex(1, 0.0).rationalize # RangeError Complex(1, 2).rationalize # RangeError
See to_r.
Returns zero as a rational. The optional argument eps is always ignored.
If a numeric is the same type as num, returns an array containing numeric and num. Otherwise, returns an array with both a numeric and num represented as Float objects.
This coercion mechanism is used by Ruby to handle mixed-type numeric operations: it is intended to find a compatible common type between the two operands of the operator.
1.coerce(2.5) #=> [2.5, 1.0] 1.2.coerce(3) #=> [3.0, 1.2] 1.coerce(2) #=> [2, 1]
Returns the smallest possible Integer that is greater than or equal to num.
Numeric achieves this by converting itself to a Float then invoking Float#ceil.
1.ceil #=> 1 1.2.ceil #=> 2 (-1.2).ceil #=> -1 (-1.0).ceil #=> -1
Splits str into an array of tokens in the same way the UNIX Bourne shell does.
See Shellwords.shellsplit for details.
Replaces the contents and taintedness of str with the corresponding values in other_str.
s = "hello" #=> "hello" s.replace "world" #=> "world"
Returns a copy of str with the first character converted to uppercase and the remainder to lowercase.
See String#downcase for meaning of options and use with different encodings.
"hello".capitalize #=> "Hello" "HELLO".capitalize #=> "Hello" "123ABC".capitalize #=> "123abc"
Modifies str by converting the first character to uppercase and the remainder to lowercase. Returns nil if no changes are made.
See String#downcase for meaning of options and use with different encodings.
a = "hello" a.capitalize! #=> "Hello" a #=> "Hello" a.capitalize! #=> nil
Divides str into substrings based on a delimiter, returning an array of these substrings.
If pattern is a String, then its contents are used as the delimiter when splitting str. If pattern is a single space, str is split on whitespace, with leading whitespace and runs of contiguous whitespace characters ignored.
If pattern is a Regexp, str is divided where the pattern matches. Whenever the pattern matches a zero-length string, str is split into individual characters. If pattern contains groups, the respective matches will be returned in the array as well.
If pattern is nil, the value of $; is used. If $; is nil (which is the default), str is split on whitespace as if ‘ ’ were specified.
If the limit parameter is omitted, trailing null fields are suppressed. If limit is a positive number, at most that number of split substrings will be returned (captured groups will be returned as well, but are not counted towards the limit). If limit is 1, the entire string is returned as the only entry in an array. If negative, there is no limit to the number of fields returned, and trailing null fields are not suppressed.
When the input str is empty an empty Array is returned as the string is considered to have no fields to split.
" now's the time".split #=> ["now's", "the", "time"] " now's the time".split(' ') #=> ["now's", "the", "time"] " now's the time".split(/ /) #=> ["", "now's", "", "the", "time"] "1, 2.34,56, 7".split(%r{,\s*}) #=> ["1", "2.34", "56", "7"] "hello".split(//) #=> ["h", "e", "l", "l", "o"] "hello".split(//, 3) #=> ["h", "e", "llo"] "hi mom".split(%r{\s*}) #=> ["h", "i", "m", "o", "m"] "mellow yellow".split("ello") #=> ["m", "w y", "w"] "1,2,,3,4,,".split(',') #=> ["1", "2", "", "3", "4"] "1,2,,3,4,,".split(',', 4) #=> ["1", "2", "", "3,4,,"] "1,2,,3,4,,".split(',', -4) #=> ["1", "2", "", "3", "4", "", ""] "1:2:3".split(/(:)()()/, 2) #=> ["1", ":", "", "", "2:3"] "".split(',', -1) #=> []
Returns an array of lines in str split using the supplied record separator ($/ by default). This is a shorthand for str.each_line(separator).to_a.
If a block is given, which is a deprecated form, works the same as each_line.
Centers str in width. If width is greater than the length of str, returns a new String of length width with str centered and padded with padstr; otherwise, returns str.
"hello".center(4) #=> "hello" "hello".center(20) #=> " hello " "hello".center(20, '123') #=> "1231231hello12312312"
Returns an array with both a numeric and a float represented as Float objects.
This is achieved by converting a numeric to a Float.
1.2.coerce(3) #=> [3.0, 1.2] 2.5.coerce(1.1) #=> [1.1, 2.5]
Returns the smallest number greater than or equal to float in decimal digits (default 0 digits).
Precision may be negative. Returns a floating point number when ndigits is positive, self for zero, and ceil up for negative.
1.2.ceil #=> 2 2.0.ceil #=> 2 (-1.2).ceil #=> -1 (-2.0).ceil #=> -2 1.234567.ceil(2) #=> 1.24 1.234567.ceil(3) #=> 1.235 1.234567.ceil(4) #=> 1.2346 1.234567.ceil(5) #=> 1.23457 34567.89.ceil(-5) #=> 100000 34567.89.ceil(-4) #=> 40000 34567.89.ceil(-3) #=> 35000 34567.89.ceil(-2) #=> 34600 34567.89.ceil(-1) #=> 34570 34567.89.ceil(0) #=> 34568 34567.89.ceil(1) #=> 34567.9 34567.89.ceil(2) #=> 34567.89 34567.89.ceil(3) #=> 34567.89
Returns a simpler approximation of the value (flt-|eps| <= result <= flt+|eps|). if the optional eps is not given, it will be chosen automatically.
0.3.rationalize #=> (3/10) 1.333.rationalize #=> (1333/1000) 1.333.rationalize(0.01) #=> (4/3)
See to_r.
Returns true if the fiber can still be resumed (or transferred to). After finishing execution of the fiber block this method will always return false. You need to require 'fiber' before using this method.
Deletes the named directory. Raises a subclass of SystemCallError if the directory isn’t empty.
Creates a new name for an existing file using a hard link. Will not overwrite new_name if it already exists (raising a subclass of SystemCallError). Not available on all platforms.
File.link("testfile", ".testfile") #=> 0 IO.readlines(".testfile")[0] #=> "This is line one\n"
Creates a symbolic link called new_name for the existing file old_name. Raises a NotImplemented exception on platforms that do not support symbolic links.
File.symlink("testfile", "link2test") #=> 0
Returns the name of the file referenced by the given link. Not available on all platforms.
File.symlink("testfile", "link2test") #=> 0 File.readlink("link2test") #=> "testfile"
Deletes the named files, returning the number of names passed as arguments. Raises an exception on any error. See also Dir::rmdir.
Splits the given string into a directory and a file component and returns them in a two-element array. See also File::dirname and File::basename.
File.split("/home/gumby/.profile") #=> ["/home/gumby", ".profile"]
Returns true if the named file is a symbolic link.
Returns true if the named file has the sticky bit set.
Returns true if the named files are identical.
file_1 and file_2 can be an IO object.
open("a", "w") {} p File.identical?("a", "a") #=> true p File.identical?("a", "./a") #=> true File.link("a", "b") p File.identical?("a", "b") #=> true File.symlink("a", "c") p File.identical?("a", "c") #=> true open("d", "w") {} p File.identical?("a", "d") #=> false