Prepends objects to the front of self
, moving other elements upwards. See also Array#shift
for the opposite effect.
a = [ "b", "c", "d" ] a.unshift("a") #=> ["a", "b", "c", "d"] a.unshift(1, 2) #=> [ 1, 2, "a", "b", "c", "d"]
Calculates the set of unambiguous abbreviations for the strings in self
.
require 'abbrev' %w{ car cone }.abbrev #=> {"car"=>"car", "ca"=>"car", "cone"=>"cone", "con"=>"cone", "co"=>"cone"}
The optional pattern
parameter is a pattern or a string. Only input strings that match the pattern or start with the string are included in the output hash.
%w{ fast boat day }.abbrev(/^.a/) #=> {"fast"=>"fast", "fas"=>"fast", "fa"=>"fast", "day"=>"day", "da"=>"day"} Abbrev.abbrev(%w{car box cone}, "ca") #=> {"car"=>"car", "ca"=>"car"}
See also Abbrev.abbrev
Allows for declaring a Gemfile inline in a ruby script, optionally installing any gems that aren’t already installed on the user’s system.
@note Every gem that is specified in this ‘Gemfile’ will be ‘require`d, as if
the user had manually called `Bundler.require`. To avoid a requested gem being automatically required, add the `:require => false` option to the `gem` dependency declaration.
@param install [Boolean] whether gems that aren’t already installed on the
user's system should be installed. Defaults to `false`.
@param gemfile [Proc] a block that is evaluated as a ‘Gemfile`.
@example Using an inline Gemfile
#!/usr/bin/env ruby require 'bundler/inline' gemfile do source 'https://rubygems.org' gem 'json', require: false gem 'nap', require: 'rest' gem 'cocoapods', '~> 0.34.1' end puts Pod::VERSION # => "0.34.4"
cgi_runner.rb – CGI
launcher.
Author: IPR – Internet Programming with Ruby – writers Copyright © 2000 TAKAHASHI Masayoshi, GOTOU YUUZOU Copyright © 2002 Internet Programming with Ruby writers. All rights reserved.
$IPR: cgi_runner.rb,v 1.9 2002/09/25 11:33:15 gotoyuzo Exp $
Prevents further modifications to obj. A RuntimeError
will be raised if modification is attempted. There is no way to unfreeze a frozen object. See also Object#frozen?
.
This method returns self.
a = [ "a", "b", "c" ] a.freeze a << "z"
produces:
prog.rb:3:in `<<': can't modify frozen Array (FrozenError) from prog.rb:3
Objects of the following classes are always frozen: Integer
, Float
, Symbol
.
Returns true
if int
is an even number.
Returns the predecessor of int
, i.e. the Integer
equal to int-1
.
1.pred #=> 0 (-1).pred #=> -2
Returns a complex object which denotes the given rectangular form.
Complex.rectangular(1, 2) #=> (1+2i)
Returns a complex object which denotes the given rectangular form.
Complex.rectangular(1, 2) #=> (1+2i)
Returns a complex object which denotes the given rectangular form.
Complex.rectangular(1, 2) #=> (1+2i)
Returns false, even if the complex number has no imaginary part.
Returns self.
Returns an array; [num, 0].
Returns an array; [num, 0].
Returns an array containing the quotient and modulus obtained by dividing num
by numeric
.
If q, r = x.divmod(y)
, then
q = floor(x/y) x = q*y + r
The quotient is rounded toward negative infinity, as shown in the following table:
a | b | a.divmod(b) | a/b | a.modulo(b) | a.remainder(b) ------+-----+---------------+---------+-------------+--------------- 13 | 4 | 3, 1 | 3 | 1 | 1 ------+-----+---------------+---------+-------------+--------------- 13 | -4 | -4, -3 | -4 | -3 | 1 ------+-----+---------------+---------+-------------+--------------- -13 | 4 | -4, 3 | -4 | 3 | -1 ------+-----+---------------+---------+-------------+--------------- -13 | -4 | 3, -1 | 3 | -1 | -1 ------+-----+---------------+---------+-------------+--------------- 11.5 | 4 | 2, 3.5 | 2.875 | 3.5 | 3.5 ------+-----+---------------+---------+-------------+--------------- 11.5 | -4 | -3, -0.5 | -2.875 | -0.5 | 3.5 ------+-----+---------------+---------+-------------+--------------- -11.5 | 4 | -3, 0.5 | -2.875 | 0.5 | -3.5 ------+-----+---------------+---------+-------------+--------------- -11.5 | -4 | 2, -3.5 | 2.875 | -3.5 | -3.5
Examples
11.divmod(3) #=> [3, 2] 11.divmod(-3) #=> [-4, -1] 11.divmod(3.5) #=> [3, 0.5] (-11).divmod(3.5) #=> [-4, 3.0] 11.5.divmod(3.5) #=> [3, 1.0]
Returns true
if num
is a real number (i.e. not Complex
).
Returns true
if num
is greater than 0.
Returns true
if num
is less than 0.
Returns true
if str has a length of zero.
"hello".empty? #=> false " ".empty? #=> false "".empty? #=> true
Replaces the contents of str with the corresponding values in other_str.
s = "hello" #=> "hello" s.replace "world" #=> "world"