Results for: "String# "

Installs the gem and returns a loaded Gem::Specification for the installed gem.

The gem will be installed with the following structure:

@gem_home/
  cache/<gem-version>.gem #=> a cached copy of the installed gem
  gems/<gem-version>/... #=> extracted files
  specifications/<gem-version>.gemspec #=> the Gem::Specification

Installs gems for this RequestSet using the Gem::Installer options.

If a block is given an activation request and installer are yielded. The installer will be nil if a gem matching the request was already installed.

Performs the uninstall of the gem. This removes the spec, the Gem directory, and the cached .gem file.

Sets userinfo, argument is string like ‘name:pass’.

Returns the userinfo, either as ‘user’ or ‘user:password’.

Returns attributes.

Setter for attributes val.

Creates a class to wrap the C struct described by signature.

MyStruct = struct ['int i', 'char c']

Writes args to the stream.

See IO#print for full details.

Formats and writes to the stream converting parameters under control of the format string.

See Kernel#sprintf for format string details.

See IO#print.

See IO#printf.

Check if gem name version version is installed.

Returns the index of a specified element.

When argument object is given but no block, returns the index of the first element element for which object == element:

a = [:foo, 'bar', 2, 'bar']
a.index('bar') # => 1

Returns nil if no such element found.

When both argument object and a block are given, calls the block with each successive element; returns the index of the first element for which the block returns a truthy value:

a = [:foo, 'bar', 2, 'bar']
a.index {|element| element == 'bar' } # => 1

Returns nil if the block never returns a truthy value.

When neither an argument nor a block is given, returns a new Enumerator:

a = [:foo, 'bar', 2]
e = a.index
e # => #<Enumerator: [:foo, "bar", 2]:index>
e.each {|element| element == 'bar' } # => 1

Array#find_index is an alias for Array#index.

Related: rindex.

Returns the singleton class of obj. This method creates a new singleton class if obj does not have one.

If obj is nil, true, or false, it returns NilClass, TrueClass, or FalseClass, respectively. If obj is an Integer, a Float or a Symbol, it raises a TypeError.

Object.new.singleton_class  #=> #<Class:#<Object:0xb7ce1e24>>
String.singleton_class      #=> #<Class:String>
nil.singleton_class         #=> NilClass

Returns an array of the names of singleton methods for obj. If the optional all parameter is true, the list will include methods in modules included in obj. Only public and protected singleton methods are returned.

module Other
  def three() end
end

class Single
  def Single.four() end
end

a = Single.new

def a.one()
end

class << a
  include Other
  def two()
  end
end

Single.singleton_methods    #=> [:four]
a.singleton_methods(false)  #=> [:two, :one]
a.singleton_methods         #=> [:two, :one, :three]

Returns true if obj is an instance of the given class. See also Object#kind_of?.

class A;     end
class B < A; end
class C < B; end

b = B.new
b.instance_of? A   #=> false
b.instance_of? B   #=> true
b.instance_of? C   #=> false

Similar to method, searches singleton method only.

class Demo
  def initialize(n)
    @iv = n
  end
  def hello()
    "Hello, @iv = #{@iv}"
  end
end

k = Demo.new(99)
def k.hi
  "Hi, @iv = #{@iv}"
end
m = k.singleton_method(:hi)
m.call   #=> "Hi, @iv = 99"
m = k.singleton_method(:hello) #=> NameError

Creates an accessor method to allow assignment to the attribute symbol.id2name. String arguments are converted to symbols. Returns an array of defined method names as symbols.

Returns an array containing the names of the public and protected instance methods in the receiver. For a module, these are the public and protected methods; for a class, they are the instance (not singleton) methods. If the optional parameter is false, the methods of any ancestors are not included.

module A
  def method1()  end
end
class B
  include A
  def method2()  end
end
class C < B
  def method3()  end
end

A.instance_methods(false)                   #=> [:method1]
B.instance_methods(false)                   #=> [:method2]
B.instance_methods(true).include?(:method1) #=> true
C.instance_methods(false)                   #=> [:method3]
C.instance_methods.include?(:method2)       #=> true

Says whether mod or its ancestors have a constant with the given name:

Float.const_defined?(:EPSILON)      #=> true, found in Float itself
Float.const_defined?("String")      #=> true, found in Object (ancestor)
BasicObject.const_defined?(:Hash)   #=> false

If mod is a Module, additionally Object and its ancestors are checked:

Math.const_defined?(:String)   #=> true, found in Object

In each of the checked classes or modules, if the constant is not present but there is an autoload for it, true is returned directly without autoloading:

module Admin
  autoload :User, 'admin/user'
end
Admin.const_defined?(:User)   #=> true

If the constant is not found the callback const_missing is not called and the method returns false.

If inherit is false, the lookup only checks the constants in the receiver:

IO.const_defined?(:SYNC)          #=> true, found in File::Constants (ancestor)
IO.const_defined?(:SYNC, false)   #=> false, not found in IO itself

In this case, the same logic for autoloading applies.

If the argument is not a valid constant name a NameError is raised with the message “wrong constant name name”:

Hash.const_defined? 'foobar'   #=> NameError: wrong constant name foobar

Makes a list of existing constants private.

Returns true if mod is a singleton class or false if it is an ordinary class or module.

class C
end
C.singleton_class?                  #=> false
C.singleton_class.singleton_class?  #=> true