Returns true if this specification is installable on this platform.
Add a certificate to trusted certificate list.
Factory for servlet instances that will handle a request from server
using options
from the mount point. By default a new servlet instance is created for every call.
Creates a string representation of self
, by calling inspect
on each element.
[ "a", "b", "c" ].to_s #=> "[\"a\", \"b\", \"c\"]"
Returns the first element, or the first n
elements, of the array. If the array is empty, the first form returns nil
, and the second form returns an empty array. See also Array#last
for the opposite effect.
a = [ "q", "r", "s", "t" ] a.first #=> "q" a.first(2) #=> ["q", "r"]
Returns the last element(s) of self
. If the array is empty, the first form returns nil
.
See also Array#first
for the opposite effect.
a = [ "w", "x", "y", "z" ] a.last #=> "z" a.last(2) #=> ["y", "z"]
Set
Intersection — Returns a new array containing unique elements common to self
and other_ary
s. Order is preserved from the original array.
It compares elements using their hash
and eql?
methods for efficiency.
[ 1, 1, 3, 5 ].intersection([ 3, 2, 1 ]) # => [ 1, 3 ] [ "a", "b", "z" ].intersection([ "a", "b", "c" ], [ "b" ]) # => [ "b" ] [ "a" ].intersection #=> [ "a" ]
See also Array#&
.
Inserts the given values before the element with the given index
.
Negative indices count backwards from the end of the array, where -1
is the last element. If a negative index is used, the given values will be inserted after that element, so using an index of -1
will insert the values at the end of the array.
a = %w{ a b c d } a.insert(2, 99) #=> ["a", "b", 99, "c", "d"] a.insert(-2, 1, 2, 3) #=> ["a", "b", 99, "c", 1, 2, 3, "d"]
Returns the number of elements in self
. May be zero.
[ 1, 2, 3, 4, 5 ].length #=> 5 [].length #=> 0
Returns the index of the first object in ary
such that the object is ==
to obj
.
If a block is given instead of an argument, returns the index of the first object for which the block returns true
. Returns nil
if no match is found.
See also Array#rindex
.
An Enumerator
is returned if neither a block nor argument is given.
a = [ "a", "b", "c" ] a.index("b") #=> 1 a.index("z") #=> nil a.index {|x| x == "b"} #=> 1
Returns a string created by converting each element of the array to a string, separated by the given separator
. If the separator
is nil
, it uses current $,
. If both the separator
and $,
are nil
, it uses an empty string.
[ "a", "b", "c" ].join #=> "abc" [ "a", "b", "c" ].join("-") #=> "a-b-c"
For nested arrays, join is applied recursively:
[ "a", [1, 2, [:x, :y]], "b" ].join("-") #=> "a-1-2-x-y-b"
Assumes that self
is an array of arrays and transposes the rows and columns.
a = [[1,2], [3,4], [5,6]] a.transpose #=> [[1, 3, 5], [2, 4, 6]]
If the length of the subarrays don’t match, an IndexError
is raised.
Returns true
if the given object
is present in self
(that is, if any element ==
object
), otherwise returns false
.
a = [ "a", "b", "c" ] a.include?("b") #=> true a.include?("z") #=> false
Returns the object in ary with the minimum value. The first form assumes all objects implement Comparable
; the second uses the block to return a <=> b.
ary = %w(albatross dog horse) ary.min #=> "albatross" ary.min {|a, b| a.length <=> b.length} #=> "dog"
If the n
argument is given, minimum n
elements are returned as an array.
ary = %w[albatross dog horse] ary.min(2) #=> ["albatross", "dog"] ary.min(2) {|a, b| a.length <=> b.length } #=> ["dog", "horse"]
Returns a two element array which contains the minimum and the maximum value in the array.
Can be given an optional block to override the default comparison method a <=> b
.
When invoked with a block, yields all combinations of length n
of elements from the array and then returns the array itself.
The implementation makes no guarantees about the order in which the combinations are yielded.
If no block is given, an Enumerator
is returned instead.
Examples:
a = [1, 2, 3, 4] a.combination(1).to_a #=> [[1],[2],[3],[4]] a.combination(2).to_a #=> [[1,2],[1,3],[1,4],[2,3],[2,4],[3,4]] a.combination(3).to_a #=> [[1,2,3],[1,2,4],[1,3,4],[2,3,4]] a.combination(4).to_a #=> [[1,2,3,4]] a.combination(0).to_a #=> [[]] # one combination of length 0 a.combination(5).to_a #=> [] # no combinations of length 5
Builds a command line string from an argument list array
joining all elements escaped for the Bourne shell and separated by a space.
See Shellwords.shelljoin
for details.
Returns a Hash
containing implementation-dependent counters inside the VM.
This hash includes information about method/constant cache serials:
{ :global_method_state=>251, :global_constant_state=>481, :class_serial=>9029 }
The contents of the hash are implementation specific and may be changed in the future.
This method is only expected to work on C Ruby.
Returns a Digest
subclass by name
in a thread-safe manner even when on-demand loading is involved.
require 'digest' Digest("MD5") # => Digest::MD5 Digest(:SHA256) # => Digest::SHA256 Digest(:Foo) # => LoadError: library not found for class Digest::Foo -- digest/foo
Returns object. This method is deprecated and will be removed in Ruby 3.2.
Returns false. This method is deprecated and will be removed in Ruby 3.2.
Returns object. This method is deprecated and will be removed in Ruby 3.2.
Returns a string containing a human-readable representation of obj. The default inspect
shows the object’s class name, an encoding of the object id, and a list of the instance variables and their values (by calling inspect
on each of them). User defined classes should override this method to provide a better representation of obj. When overriding this method, it should return a string whose encoding is compatible with the default external encoding.
[ 1, 2, 3..4, 'five' ].inspect #=> "[1, 2, 3..4, \"five\"]" Time.new.inspect #=> "2008-03-08 19:43:39 +0900" class Foo end Foo.new.inspect #=> "#<Foo:0x0300c868>" class Bar def initialize @bar = 1 end end Bar.new.inspect #=> "#<Bar:0x0300c868 @bar=1>"