Returns the subgroups in the most recent match (not including the full match). If nothing was priorly matched, it returns nil.
s = StringScanner.new("Fri Dec 12 1975 14:39") s.scan(/(\w+) (\w+) (\d+) /) # -> "Fri Dec 12 " s.captures # -> ["Fri", "Dec", "12"] s.scan(/(\w+) (\w+) (\d+) /) # -> nil s.captures # -> nil
Returns running OLE Automation object or WIN32OLE object from moniker. 1st argument should be OLE program id or class id or moniker.
WIN32OLE.connect('Excel.Application') # => WIN32OLE object which represents running Excel.
Sets current codepage. The WIN32OLE.codepage is initialized according to Encoding.default_internal. If Encoding.default_internal is nil then WIN32OLE.codepage is initialized according to Encoding.default_external.
WIN32OLE.codepage = WIN32OLE::CP_UTF8 WIN32OLE.codepage = 65001
Invokes the method identified by symbol, passing it any arguments specified. When the method is identified by a string, the string is converted to a symbol.
BasicObject implements __send__, Kernel implements send. __send__ is safer than send when obj has the same method name like Socket. See also public_send.
class Klass def hello(*args) "Hello " + args.join(' ') end end k = Klass.new k.send :hello, "gentle", "readers" #=> "Hello gentle readers"
Returns true if there are no hash entries, false otherwise:
{}.empty? # => true
{foo: 0, bar: 1, baz: 2}.empty? # => false
Hash#filter is an alias for Hash#select.
Returns a new Hash object whose entries are those for which the block returns a truthy value:
h = {foo: 0, bar: 1, baz: 2} h.select {|key, value| value < 2 } # => {:foo=>0, :bar=>1}
Returns a new Enumerator if no block given:
h = {foo: 0, bar: 1, baz: 2} e = h.select # => #<Enumerator: {:foo=>0, :bar=>1, :baz=>2}:select> e.each {|key, value| value < 2 } # => {:foo=>0, :bar=>1}
Hash#filter! is an alias for Hash#select!.
Returns self, whose entries are those for which the block returns a truthy value:
h = {foo: 0, bar: 1, baz: 2}
h.select! {|key, value| value < 2 } => {:foo=>0, :bar=>1}
Returns nil if no entries were removed.
Returns a new Enumerator if no block given:
h = {foo: 0, bar: 1, baz: 2} e = h.select! # => #<Enumerator: {:foo=>0, :bar=>1, :baz=>2}:select!> e.each { |key, value| value < 2 } # => {:foo=>0, :bar=>1}
Hash#filter is an alias for Hash#select.
Returns a new Hash object whose entries are those for which the block returns a truthy value:
h = {foo: 0, bar: 1, baz: 2} h.select {|key, value| value < 2 } # => {:foo=>0, :bar=>1}
Returns a new Enumerator if no block given:
h = {foo: 0, bar: 1, baz: 2} e = h.select # => #<Enumerator: {:foo=>0, :bar=>1, :baz=>2}:select> e.each {|key, value| value < 2 } # => {:foo=>0, :bar=>1}
Hash#filter! is an alias for Hash#select!.
Returns self, whose entries are those for which the block returns a truthy value:
h = {foo: 0, bar: 1, baz: 2}
h.select! {|key, value| value < 2 } => {:foo=>0, :bar=>1}
Returns nil if no entries were removed.
Returns a new Enumerator if no block given:
h = {foo: 0, bar: 1, baz: 2} e = h.select! # => #<Enumerator: {:foo=>0, :bar=>1, :baz=>2}:select!> e.each { |key, value| value < 2 } # => {:foo=>0, :bar=>1}
Returns a new Hash excluding entries for the given keys:
h = { a: 100, b: 200, c: 300 } h.except(:a) #=> {:b=>200, :c=>300}
Any given keys that are not found are ignored.
Removes all hash entries; returns self.
Returns a new Hash object with the each key-value pair inverted:
h = {foo: 0, bar: 1, baz: 2} h1 = h.invert h1 # => {0=>:foo, 1=>:bar, 2=>:baz}
Overwrites any repeated new keys: (see Entry Order):
h = {foo: 0, bar: 0, baz: 0} h.invert # => {0=>:baz}
Merges each of other_hashes into self; returns self.
Each argument in other_hashes must be a Hash.
Method update is an alias for #merge!.
With arguments and no block:
Returns self, after the given hashes are merged into it.
The given hashes are merged left to right.
Each new entry is added at the end.
Each duplicate-key entry’s value overwrites the previous value.
Example:
h = {foo: 0, bar: 1, baz: 2} h1 = {bat: 3, bar: 4} h2 = {bam: 5, bat:6} h.merge!(h1, h2) # => {:foo=>0, :bar=>4, :baz=>2, :bat=>6, :bam=>5}
With arguments and a block:
Returns self, after the given hashes are merged.
The given hashes are merged left to right.
Each new-key entry is added at the end.
For each duplicate key:
Calls the block with the key and the old and new values.
The block’s return value becomes the new value for the entry.
Example:
h = {foo: 0, bar: 1, baz: 2} h1 = {bat: 3, bar: 4} h2 = {bam: 5, bat:6} h3 = h.merge!(h1, h2) { |key, old_value, new_value| old_value + new_value } h3 # => {:foo=>0, :bar=>5, :baz=>2, :bat=>9, :bam=>5}
With no arguments:
Returns self, unmodified.
The block, if given, is ignored.
Example:
h = {foo: 0, bar: 1, baz: 2} h.merge # => {:foo=>0, :bar=>1, :baz=>2} h1 = h.merge! { |key, old_value, new_value| raise 'Cannot happen' } h1 # => {:foo=>0, :bar=>1, :baz=>2}
Returns the new Hash formed by merging each of other_hashes into a copy of self.
Each argument in other_hashes must be a Hash.
With arguments and no block:
Returns the new Hash object formed by merging each successive Hash in other_hashes into self.
Each new-key entry is added at the end.
Each duplicate-key entry’s value overwrites the previous value.
Example:
h = {foo: 0, bar: 1, baz: 2} h1 = {bat: 3, bar: 4} h2 = {bam: 5, bat:6} h.merge(h1, h2) # => {:foo=>0, :bar=>4, :baz=>2, :bat=>6, :bam=>5}
With arguments and a block:
Returns a new Hash object that is the merge of self and each given hash.
The given hashes are merged left to right.
Each new-key entry is added at the end.
For each duplicate key:
Calls the block with the key and the old and new values.
The block’s return value becomes the new value for the entry.
Example:
h = {foo: 0, bar: 1, baz: 2} h1 = {bat: 3, bar: 4} h2 = {bam: 5, bat:6} h3 = h.merge(h1, h2) { |key, old_value, new_value| old_value + new_value } h3 # => {:foo=>0, :bar=>5, :baz=>2, :bat=>9, :bam=>5}
With no arguments:
Returns a copy of self.
The block, if given, is ignored.
Example:
h = {foo: 0, bar: 1, baz: 2} h.merge # => {:foo=>0, :bar=>1, :baz=>2} h1 = h.merge { |key, old_value, new_value| raise 'Cannot happen' } h1 # => {:foo=>0, :bar=>1, :baz=>2}
Returns a copy of self with all nil-valued entries removed:
h = {foo: 0, bar: nil, baz: 2, bat: nil} h1 = h.compact h1 # => {:foo=>0, :baz=>2}
Returns self with all its nil-valued entries removed (in place):
h = {foo: 0, bar: nil, baz: 2, bat: nil} h.compact! # => {:foo=>0, :baz=>2}
Returns nil if no entries were removed.
Methods has_key?, key?, and member? are aliases for #include?.
Returns true if key is a key in self, otherwise false.
Returns a hash except the given keys from ENV and their values.
ENV #=> {"LANG"=>"en_US.UTF-8", "TERM"=>"xterm-256color", "HOME"=>"/Users/rhc"} ENV.except("TERM","HOME") #=> {"LANG"=>"en_US.UTF-8"}
Removes every environment variable; returns ENV:
ENV.replace('foo' => '0', 'bar' => '1') ENV.size # => 2 ENV.clear # => ENV ENV.size # => 0
ENV.filter is an alias for ENV.select.
Yields each environment variable name and its value as a 2-element Array, returning a Hash of the names and values for which the block returns a truthy value:
ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2') ENV.select { |name, value| name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"} ENV.filter { |name, value| name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"}
Returns an Enumerator if no block given:
e = ENV.select # => #<Enumerator: {"bar"=>"1", "baz"=>"2", "foo"=>"0"}:select> e.each { |name, value | name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"} e = ENV.filter # => #<Enumerator: {"bar"=>"1", "baz"=>"2", "foo"=>"0"}:filter> e.each { |name, value | name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"}
ENV.filter! is an alias for ENV.select!.
Yields each environment variable name and its value as a 2-element Array, deleting each entry for which the block returns false or nil, and returning ENV if any deletions made, or nil otherwise:
ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2') ENV.select! { |name, value| name.start_with?('b') } # => ENV ENV # => {"bar"=>"1", "baz"=>"2"} ENV.select! { |name, value| true } # => nil ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2') ENV.filter! { |name, value| name.start_with?('b') } # => ENV ENV # => {"bar"=>"1", "baz"=>"2"} ENV.filter! { |name, value| true } # => nil
Returns an Enumerator if no block given:
ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2') e = ENV.select! # => #<Enumerator: {"bar"=>"1", "baz"=>"2"}:select!> e.each { |name, value| name.start_with?('b') } # => ENV ENV # => {"bar"=>"1", "baz"=>"2"} e.each { |name, value| true } # => nil ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2') e = ENV.filter! # => #<Enumerator: {"bar"=>"1", "baz"=>"2"}:filter!> e.each { |name, value| name.start_with?('b') } # => ENV ENV # => {"bar"=>"1", "baz"=>"2"} e.each { |name, value| true } # => nil
ENV.filter is an alias for ENV.select.
Yields each environment variable name and its value as a 2-element Array, returning a Hash of the names and values for which the block returns a truthy value:
ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2') ENV.select { |name, value| name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"} ENV.filter { |name, value| name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"}
Returns an Enumerator if no block given:
e = ENV.select # => #<Enumerator: {"bar"=>"1", "baz"=>"2", "foo"=>"0"}:select> e.each { |name, value | name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"} e = ENV.filter # => #<Enumerator: {"bar"=>"1", "baz"=>"2", "foo"=>"0"}:filter> e.each { |name, value | name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"}
ENV.filter! is an alias for ENV.select!.
Yields each environment variable name and its value as a 2-element Array, deleting each entry for which the block returns false or nil, and returning ENV if any deletions made, or nil otherwise:
ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2') ENV.select! { |name, value| name.start_with?('b') } # => ENV ENV # => {"bar"=>"1", "baz"=>"2"} ENV.select! { |name, value| true } # => nil ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2') ENV.filter! { |name, value| name.start_with?('b') } # => ENV ENV # => {"bar"=>"1", "baz"=>"2"} ENV.filter! { |name, value| true } # => nil
Returns an Enumerator if no block given:
ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2') e = ENV.select! # => #<Enumerator: {"bar"=>"1", "baz"=>"2"}:select!> e.each { |name, value| name.start_with?('b') } # => ENV ENV # => {"bar"=>"1", "baz"=>"2"} e.each { |name, value| true } # => nil ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2') e = ENV.filter! # => #<Enumerator: {"bar"=>"1", "baz"=>"2"}:filter!> e.each { |name, value| name.start_with?('b') } # => ENV ENV # => {"bar"=>"1", "baz"=>"2"} e.each { |name, value| true } # => nil
Returns a Hash whose keys are the ENV values, and whose values are the corresponding ENV names:
ENV.replace('foo' => '0', 'bar' => '1') ENV.invert # => {"1"=>"bar", "0"=>"foo"}
For a duplicate ENV value, overwrites the hash entry:
ENV.replace('foo' => '0', 'bar' => '0') ENV.invert # => {"0"=>"foo"}
Note that the order of the ENV processing is OS-dependent, which means that the order of overwriting is also OS-dependent. See About Ordering.