Writes self on the given port:
1.display "cat".display [ 4, 5, 6 ].display puts
Output:
1cat[4, 5, 6]
Divide by the specified value.
If specified and less than the number of significant digits of the result, the result is rounded to that number of digits, according to BigDecimal.mode.
If digits is 0, the result is the same as for the / operator or quo.
If digits is not specified, the result is an integer, by analogy with Float#div; see also BigDecimal#divmod.
See BigDecimal#/. See BigDecimal#quo.
Examples:
a = BigDecimal("4") b = BigDecimal("3") a.div(b, 3) # => 0.133e1 a.div(b, 0) # => 0.1333333333333333333e1 a / b # => 0.1333333333333333333e1 a.quo(b) # => 0.1333333333333333333e1 a.div(b) # => 1
Divides by the specified value, and returns the quotient and modulus as BigDecimal numbers. The quotient is rounded towards negative infinity.
For example:
require 'bigdecimal' a = BigDecimal("42") b = BigDecimal("9") q, m = a.divmod(b) c = q * b + m a == c #=> true
The quotient q is (a/b).floor, and the modulus is the amount that must be added to q * b to get a.
Performs division and returns the value as a Float.
Rational(2, 3).fdiv(1) #=> 0.6666666666666666 Rational(2, 3).fdiv(0.5) #=> 1.3333333333333333 Rational(2).fdiv(3) #=> 0.6666666666666666
Synonym for $stdin.
Returns a new Date object formed fom the arguments.
With no arguments, returns the date for January 1, -4712:
Date.ordinal.to_s # => "-4712-01-01"
With argument year, returns the date for January 1 of that year:
Date.ordinal(2001).to_s # => "2001-01-01" Date.ordinal(-2001).to_s # => "-2001-01-01"
With positive argument yday == n, returns the date for the nth day of the given year:
Date.ordinal(2001, 14).to_s # => "2001-01-14"
With negative argument yday, counts backward from the end of the year:
Date.ordinal(2001, -14).to_s # => "2001-12-18"
Raises an exception if yday is zero or out of range.
See argument start.
Creates a DateTime object denoting the given ordinal date.
DateTime.ordinal(2001,34) #=> #<DateTime: 2001-02-03T00:00:00+00:00 ...> DateTime.ordinal(2001,34,4,5,6,'+7') #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...> DateTime.ordinal(2001,-332,-20,-55,-54,'+7') #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
Finds and returns the object in nested objects that is specified by name and identifiers. The nested objects may be instances of various classes. See Dig Methods.
Examples:
require "ostruct" address = OpenStruct.new("city" => "Anytown NC", "zip" => 12345) person = OpenStruct.new("name" => "John Smith", "address" => address) person.dig(:address, "zip") # => 12345 person.dig(:business_address, "zip") # => nil
With no argument, returns the first element of self, if it exists:
(1..4).first # => 1 ('a'..'d').first # => "a"
With non-negative integer argument n given, returns the first n elements in an array:
(1..10).first(3) # => [1, 2, 3] (1..10).first(0) # => [] (1..4).first(50) # => [1, 2, 3, 4]
Raises an exception if there is no first element:
(..4).first # Raises RangeError
Returns the Encoding object that represents the encoding of obj.
Returns true if the set and the given enumerable have no element in common. This method is the opposite of intersect?.
Set[1, 2, 3].disjoint? Set[3, 4] #=> false Set[1, 2, 3].disjoint? Set[4, 5] #=> true Set[1, 2, 3].disjoint? [3, 4] #=> false Set[1, 2, 3].disjoint? 4..5 #=> true
Divides the set into a set of subsets according to the commonality defined by the given block.
If the arity of the block is 2, elements o1 and o2 are in common if block.call(o1, o2) is true. Otherwise, elements o1 and o2 are in common if block.call(o1) == block.call(o2).
require 'set' numbers = Set[1, 3, 4, 6, 9, 10, 11] set = numbers.divide { |i,j| (i - j).abs == 1 } set #=> #<Set: {#<Set: {1}>, # #<Set: {11, 9, 10}>, # #<Set: {3, 4}>, # #<Set: {6}>}>
Returns an enumerator if no block is given.
Finds and returns an object among nested objects. The nested objects may be instances of various classes. See Dig Methods.
Given symbol or string argument name, returns the object that is specified by name and identifiers:
Foo = Struct.new(:a) f = Foo.new(Foo.new({b: [1, 2, 3]})) f.dig(:a) # => #<struct Foo a={:b=>[1, 2, 3]}> f.dig(:a, :a) # => {:b=>[1, 2, 3]} f.dig(:a, :a, :b) # => [1, 2, 3] f.dig(:a, :a, :b, 0) # => 1 f.dig(:b, 0) # => nil
Given integer argument n, returns the object that is specified by n and identifiers:
f.dig(0) # => #<struct Foo a={:b=>[1, 2, 3]}> f.dig(0, 0) # => {:b=>[1, 2, 3]} f.dig(0, 0, :b) # => [1, 2, 3] f.dig(0, 0, :b, 0) # => 1 f.dig(:b, 0) # => nil
Equivalent to self.to_s.encoding; see String#encoding.
Returns the birth time for the file. If the platform doesn’t have birthtime, raises NotImplementedError.
See File.birthtime.
Return encoding of the source.
Creates a pair of sockets connected each other.
domain should be a communications domain such as: :INET, :INET6, :UNIX, etc.
socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.
protocol should be a protocol defined in the domain, defaults to 0 for the domain.
s1, s2 = Socket.pair(:UNIX, :STREAM, 0) s1.send "a", 0 s1.send "b", 0 s1.close p s2.recv(10) #=> "ab" p s2.recv(10) #=> "" p s2.recv(10) #=> "" s1, s2 = Socket.pair(:UNIX, :DGRAM, 0) s1.send "a", 0 s1.send "b", 0 p s2.recv(10) #=> "a" p s2.recv(10) #=> "b"
Creates a pair of sockets connected each other.
domain should be a communications domain such as: :INET, :INET6, :UNIX, etc.
socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.
protocol should be a protocol defined in the domain, defaults to 0 for the domain.
s1, s2 = Socket.pair(:UNIX, :STREAM, 0) s1.send "a", 0 s1.send "b", 0 s1.close p s2.recv(10) #=> "ab" p s2.recv(10) #=> "" p s2.recv(10) #=> "" s1, s2 = Socket.pair(:UNIX, :DGRAM, 0) s1.send "a", 0 s1.send "b", 0 p s2.recv(10) #=> "a" p s2.recv(10) #=> "b"
Creates a pair of sockets connected to each other.
socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.
protocol should be a protocol defined in the domain. 0 is default protocol for the domain.
s1, s2 = UNIXSocket.pair s1.send "a", 0 s1.send "b", 0 p s2.recv(10) #=> "ab"
Creates a pair of sockets connected to each other.
socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.
protocol should be a protocol defined in the domain. 0 is default protocol for the domain.
s1, s2 = UNIXSocket.pair s1.send "a", 0 s1.send "b", 0 p s2.recv(10) #=> "ab"
Finds and returns the object in nested objects that is specified by key and identifiers. The nested objects may be instances of various classes. See Dig Methods.
Nested Hashes:
h = {foo: {bar: {baz: 2}}} h.dig(:foo) # => {:bar=>{:baz=>2}} h.dig(:foo, :bar) # => {:baz=>2} h.dig(:foo, :bar, :baz) # => 2 h.dig(:foo, :bar, :BAZ) # => nil
Nested Hashes and Arrays:
h = {foo: {bar: [:a, :b, :c]}} h.dig(:foo, :bar, 2) # => :c
This method will use the default values for keys that are not present:
h = {foo: {bar: [:a, :b, :c]}} h.dig(:hello) # => nil h.default_proc = -> (hash, _key) { hash } h.dig(:hello, :world) # => h h.dig(:hello, :world, :foo, :bar, 2) # => :c
Opens an IRB session where binding.irb is called which allows for interactive debugging. You can call any methods or variables available in the current scope, and mutate state if you need to.
Given a Ruby file called potato.rb containing the following code:
class Potato def initialize @cooked = false binding.irb puts "Cooked potato: #{@cooked}" end end Potato.new
Running ruby potato.rb will open an IRB session where binding.irb is called, and you will see the following:
$ ruby potato.rb
From: potato.rb @ line 4 :
1: class Potato
2: def initialize
3: @cooked = false
=> 4: binding.irb
5: puts "Cooked potato: #{@cooked}"
6: end
7: end
8:
9: Potato.new
irb(#<Potato:0x00007feea1916670>):001:0>
You can type any valid Ruby code and it will be evaluated in the current context. This allows you to debug without having to run your code repeatedly:
irb(#<Potato:0x00007feea1916670>):001:0> @cooked => false irb(#<Potato:0x00007feea1916670>):002:0> self.class => Potato irb(#<Potato:0x00007feea1916670>):003:0> caller.first => ".../2.5.1/lib/ruby/2.5.0/irb/workspace.rb:85:in `eval'" irb(#<Potato:0x00007feea1916670>):004:0> @cooked = true => true
You can exit the IRB session with the exit command. Note that exiting will resume execution where binding.irb had paused it, as you can see from the output printed to standard output in this example:
irb(#<Potato:0x00007feea1916670>):005:0> exit Cooked potato: true
See IRB Usage at IRB for more information.
Parses environment variable env or its uppercase with splitting like a shell.
env defaults to the basename of the program.