Executes the given block within the context of the receiver (obj). In order to set the context, the variable self
is set to obj while the code is executing, giving the code access to obj’s instance variables. Arguments are passed as block parameters.
class KlassWithSecret def initialize @secret = 99 end end k = KlassWithSecret.new k.instance_exec(5) {|x| @secret+x } #=> 104
Replaces the entire contents of self
with the contents of other_hash
; returns self
:
h = {foo: 0, bar: 1, baz: 2} h.replace({bat: 3, bam: 4}) # => {:bat=>3, :bam=>4}
Calls the given block with each value; returns self
:
h = {foo: 0, bar: 1, baz: 2} h.each_value {|value| puts value } # => {:foo=>0, :bar=>1, :baz=>2}
Output:
0 1 2
Returns a new Enumerator if no block given:
h = {foo: 0, bar: 1, baz: 2} e = h.each_value # => #<Enumerator: {:foo=>0, :bar=>1, :baz=>2}:each_value> h1 = e.each {|value| puts value } h1 # => {:foo=>0, :bar=>1, :baz=>2}
Output:
0 1 2
Returns a new Hash object; each entry has:
A key from self
.
A value provided by the block.
Transform values:
h = {foo: 0, bar: 1, baz: 2} h1 = h.transform_values {|value| value * 100} h1 # => {:foo=>0, :bar=>100, :baz=>200}
Returns a new Enumerator if no block given:
h = {foo: 0, bar: 1, baz: 2} e = h.transform_values # => #<Enumerator: {:foo=>0, :bar=>1, :baz=>2}:transform_values> h1 = e.each { |value| value * 100} h1 # => {:foo=>0, :bar=>100, :baz=>200}
Returns self
, whose keys are unchanged, and whose values are determined by the given block.
h = {foo: 0, bar: 1, baz: 2} h.transform_values! {|value| value * 100} # => {:foo=>0, :bar=>100, :baz=>200}
Returns a new Enumerator if no block given:
h = {foo: 0, bar: 1, baz: 2} e = h.transform_values! # => #<Enumerator: {:foo=>0, :bar=>100, :baz=>200}:transform_values!> h1 = e.each {|value| value * 100} h1 # => {:foo=>0, :bar=>100, :baz=>200}
Returns a new Array containing values for the given keys
:
h = {foo: 0, bar: 1, baz: 2} h.values_at(:baz, :foo) # => [2, 0]
The default values are returned for any keys that are not found:
h.values_at(:hello, :foo) # => [nil, 0]
Returns a new Array containing the values associated with the given keys *keys:
h = {foo: 0, bar: 1, baz: 2} h.fetch_values(:baz, :foo) # => [2, 0]
Returns a new empty Array if no arguments given.
When a block is given, calls the block with each missing key, treating the block’s return value as the value for that key:
h = {foo: 0, bar: 1, baz: 2} values = h.fetch_values(:bar, :foo, :bad, :bam) {|key| key.to_s} values # => [1, 0, "bad", "bam"]
When no block is given, raises an exception if any given key is not found.
Returns true
if value
is a value in self
, otherwise false
.
Yields each environment variable value:
ENV.replace('foo' => '0', 'bar' => '1') # => ENV values = [] ENV.each_value { |value| values.push(value) } # => ENV values # => ["1", "0"]
Returns an Enumerator
if no block given:
e = ENV.each_value # => #<Enumerator: {"bar"=>"1", "foo"=>"0"}:each_value> values = [] e.each { |value| values.push(value) } # => ENV values # => ["1", "0"]
Returns an Array
containing the environment variable values associated with the given names:
ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2') ENV.values_at('foo', 'baz') # => ["0", "2"]
Returns nil
in the Array
for each name that is not an ENV
name:
ENV.values_at('foo', 'bat', 'bar', 'bam') # => ["0", nil, "1", nil]
Returns an empty Array if no names given.
Raises an exception if any name is invalid. See Invalid Names and Values.
Returns true
if value
is the value for some environment variable name, false
otherwise:
ENV.replace('foo' => '0', 'bar' => '1') ENV.value?('0') # => true ENV.has_value?('0') # => true ENV.value?('2') # => false ENV.has_value?('2') # => false
Returns the external encoding for files read from ARGF
as an Encoding
object. The external encoding is the encoding of the text as stored in a file. Contrast with ARGF.internal_encoding
, which is the encoding used to represent this text within Ruby.
To set the external encoding use ARGF.set_encoding
.
For example:
ARGF.external_encoding #=> #<Encoding:UTF-8>
Returns the internal encoding for strings read from ARGF
as an Encoding
object.
If ARGF.set_encoding
has been called with two encoding names, the second is returned. Otherwise, if Encoding.default_external
has been set, that value is returned. Failing that, if a default external encoding was specified on the command-line, that value is used. If the encoding is unknown, nil
is returned.
Returns the value that determines whether illegal input is to be handled; used for parsing; see {Option liberal_parsing
}:
CSV.new('').liberal_parsing? # => false
Serialization support for the object returned by _getobj_.
Reinitializes delegation from a serialized object.
Returns true if the ipaddr is a link-local address. IPv4 addresses in 169.254.0.0/16 reserved by RFC 3927 and Link-Local IPv6 Unicast Addresses in fe80::/10 reserved by RFC 4291 are considered link-local.
Returns the names of the binding’s local variables as symbols.
def foo a = 1 2.times do |n| binding.local_variables #=> [:a, :n] end end
This method is the short version of the following code:
binding.eval("local_variables")
Called for dup & clone.
Called for dup & clone.
Add option switch like with on
, but at tail of summary.