Downcases the contents of str, returning nil if no changes were made.
See String#downcase for meaning of options and use with different encodings.
Treats leading characters of str as a string of octal digits (with an optional sign) and returns the corresponding number. Returns 0 if the conversion fails.
"123".oct #=> 83 "-377".oct #=> -255 "bad".oct #=> 0 "0377bad".oct #=> 255
If str starts with 0, radix indicators are honored. See Kernel#Integer.
Returns true if str contains the given string or character.
"hello".include? "lo" #=> true "hello".include? "ol" #=> false "hello".include? ?h #=> true
Each other_str parameter defines a set of characters to count. The intersection of these sets defines the characters to count in str. Any other_str that starts with a caret ^ is negated. The sequence c1-c2 means all characters between c1 and c2. The backslash character \ can be used to escape ^ or - and is otherwise ignored unless it appears at the end of a sequence or the end of a other_str.
a = "hello world" a.count "lo" #=> 5 a.count "lo", "o" #=> 2 a.count "hello", "^l" #=> 4 a.count "ej-m" #=> 4 "hello^world".count "\\^aeiou" #=> 4 "hello-world".count "a\\-eo" #=> 4 c = "hello world\\r\\n" c.count "\\" #=> 2 c.count "\\A" #=> 0 c.count "X-\\w" #=> 3
provides a unified clone operation, for REXML::XPathParser to use across multiple Object types
Returns float rounded to the nearest value with a precision of ndigits decimal digits (default: 0).
When the precision is negative, the returned value is an integer with at least ndigits.abs trailing zeros.
Returns a floating point number when ndigits is positive, otherwise returns an integer.
1.4.round #=> 1 1.5.round #=> 2 1.6.round #=> 2 (-1.5).round #=> -2 1.234567.round(2) #=> 1.23 1.234567.round(3) #=> 1.235 1.234567.round(4) #=> 1.2346 1.234567.round(5) #=> 1.23457 34567.89.round(-5) #=> 0 34567.89.round(-4) #=> 30000 34567.89.round(-3) #=> 35000 34567.89.round(-2) #=> 34600 34567.89.round(-1) #=> 34570 34567.89.round(0) #=> 34568 34567.89.round(1) #=> 34567.9 34567.89.round(2) #=> 34567.89 34567.89.round(3) #=> 34567.89
If the optional half keyword argument is given, numbers that are half-way between two possible rounded values will be rounded according to the specified tie-breaking mode:
:up or nil: round half away from zero (default)
:down: round half toward zero
:even: round half toward the nearest even number
2.5.round(half: :up) #=> 3 2.5.round(half: :down) #=> 2 2.5.round(half: :even) #=> 2 3.5.round(half: :up) #=> 4 3.5.round(half: :down) #=> 3 3.5.round(half: :even) #=> 4 (-2.5).round(half: :up) #=> -3 (-2.5).round(half: :down) #=> -2 (-2.5).round(half: :even) #=> -2
Returns true if float is greater than 0.
Returns true if float is less than 0.
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.
Returns fiber information string.
Return a string describing this Dir object.
Deletes the named directory. Raises a subclass of SystemCallError if the directory isn’t empty.
Returns the last access time for the named file as a Time object.
file_name can be an IO object.
File.atime("testfile") #=> Wed Apr 09 08:51:48 CDT 2003
Returns the modification time for the named file as a Time object.
file_name can be an IO object.
File.mtime("testfile") #=> Tue Apr 08 12:58:04 CDT 2003
Returns the birth time for the named file.
file_name can be an IO object.
File.birthtime("testfile") #=> Wed Apr 09 08:53:13 CDT 2003
If the platform doesn’t have birthtime, raises NotImplementedError.
Sets the access and modification times of each named file to the first two arguments. If a file is a symlink, this method acts upon its referent rather than the link itself; for the inverse behavior see File.lutime. Returns the number of file names in the argument list.
Sets the access and modification times of each named file to the first two arguments. If a file is a symlink, this method acts upon the link itself as opposed to its referent; for the inverse behavior, see File.utime. Returns the number of file names in the argument list.
Deletes the named files, returning the number of names passed as arguments. Raises an exception on any error. Since the underlying implementation relies on the unlink(2) system call, the type of exception raised depends on its error type (see linux.die.net/man/2/unlink) and has the form of e.g. Errno::ENOENT.
See also Dir::rmdir.
Returns the last access time (a Time object) for file, or epoch if file has not been accessed.
File.new("testfile").atime #=> Wed Dec 31 18:00:00 CST 1969
Returns the modification time for file.
File.new("testfile").mtime #=> Wed Apr 09 08:53:14 CDT 2003
Returns the birth time for file.
File.new("testfile").birthtime #=> Wed Apr 09 08:53:14 CDT 2003
If the platform doesn’t have birthtime, raises NotImplementedError.
Returns true if the named file is a directory, or a symlink that points at a directory, and false otherwise.
file_name can be an IO object.
File.directory?(".")
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
Returns a string which represents the encoding for programmers.
Encoding::UTF_8.inspect #=> "#<Encoding:UTF-8>" Encoding::ISO_2022_JP.inspect #=> "#<Encoding:ISO-2022-JP (dummy)>"