Synonym for ENV
.
Implemented for compatibility; returns true
unless jd
is invalid (i.e., not a Numeric
).
Date.valid_jd?(2451944) # => true
See argument start.
Related: Date.jd
.
Returns true
if the arguments define a valid ordinal date, false
otherwise:
Date.valid_date?(2001, 2, 3) # => true Date.valid_date?(2001, 2, 29) # => false Date.valid_date?(2001, 2, -1) # => true
See argument start.
Returns true
if the arguments define a valid ordinal date, false
otherwise:
Date.valid_date?(2001, 2, 3) # => true Date.valid_date?(2001, 2, 29) # => false Date.valid_date?(2001, 2, -1) # => true
See argument start.
Returns a copy of self
with the given start
value:
d0 = Date.new(2000, 2, 3) d0.julian? # => false d1 = d0.new_start(Date::JULIAN) d1.julian? # => true
See argument start.
Scrolls the entire scrolls forward n
lines.
You must require ‘io/console’ to use this method.
Scrolls the entire scrolls backward n
lines.
You must require ‘io/console’ to use this method.
Waits until IO
is writable and returns a truthy value or a falsy value when times out.
You must require ‘io/wait’ to use this method.
Returns the Encoding
object that represents the encoding of the stream, or nil
if the stream is in write mode and no encoding is specified.
See Encodings.
Returns the Encoding
object that represents the encoding of the internal string, if conversion is specified, or nil
otherwise.
See Encodings.
Dup internal hash.
Clone internal hash.
Returns an array of values from self
.
With integer arguments integers
given, returns an array containing each value given by one of integers
:
Customer = Struct.new(:name, :address, :zip) joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345) joe.values_at(0, 2) # => ["Joe Smith", 12345] joe.values_at(2, 0) # => [12345, "Joe Smith"] joe.values_at(2, 1, 0) # => [12345, "123 Maple, Anytown NC", "Joe Smith"] joe.values_at(0, -3) # => ["Joe Smith", "Joe Smith"]
Raises IndexError
if any of integers
is out of range; see Array Indexes at Array
.
With integer range argument integer_range
given, returns an array containing each value given by the elements of the range; fills with nil
values for range elements larger than the structure:
joe.values_at(0..2) # => ["Joe Smith", "123 Maple, Anytown NC", 12345] joe.values_at(-3..-1) # => ["Joe Smith", "123 Maple, Anytown NC", 12345] joe.values_at(1..4) # => ["123 Maple, Anytown NC", 12345, nil, nil]
Raises RangeError
if any element of the range is negative and out of range; see Array Indexes at Array
.
Equivalent to self.to_s.start_with?
; see String#start_with?
.
Returns true if this class can be used to create an instance from a serialised JSON
string. The class has to implement a class method json_create that expects a hash as first parameter. The hash should include the required data.
Returns the object for which the receiver is the singleton class.
Raises an TypeError
if the class is not a singleton class.
class Foo; end Foo.singleton_class.attached_object #=> Foo Foo.attached_object #=> TypeError: `Foo' is not a singleton class Foo.new.singleton_class.attached_object #=> #<Foo:0x000000010491a370> TrueClass.attached_object #=> TypeError: `TrueClass' is not a singleton class NilClass.attached_object #=> TypeError: `NilClass' is not a singleton class
Returns an Addrinfo
object for local address obtained by getsockname.
Note that addrinfo.protocol is filled by 0.
TCPSocket.open("www.ruby-lang.org", 80) {|s| p s.local_address #=> #<Addrinfo: 192.168.0.129:36873 TCP> } TCPServer.open("127.0.0.1", 1512) {|serv| p serv.local_address #=> #<Addrinfo: 127.0.0.1:1512 TCP> }
creates an Addrinfo
object from the arguments.
The arguments are interpreted as similar to self.
Addrinfo.tcp("0.0.0.0", 4649).family_addrinfo("www.ruby-lang.org", 80) #=> #<Addrinfo: 221.186.184.68:80 TCP (www.ruby-lang.org:80)> Addrinfo.unix("/tmp/sock").family_addrinfo("/tmp/sock2") #=> #<Addrinfo: /tmp/sock2 SOCK_STREAM>
creates a new Socket
connected to the address of local_addrinfo
.
If local_addrinfo is nil, the address of the socket is not bound.
The timeout specify the seconds for timeout. Errno::ETIMEDOUT is raised when timeout occur.
If a block is given the created socket is yielded for each address.
Returns true for IPv6 link local address (fe80::/10). It returns false otherwise.
Returns true for IPv6 site local address (fec0::/10). It returns false otherwise.