What Is the Opposite of Ruby's Include

Ruby: Is there an opposite of include? for Ruby Arrays?

if @players.exclude?(p.name)
    ...
end

ActiveSupport adds the exclude? method to Array, Hash, and String. This is not pure Ruby, but is used by a LOT of rubyists.

Source: Active Support Core Extensions (Rails Guides)

Opposite of includes in Rails

You can use the unscoped scope. Method reference: http://apidock.com/rails/ActiveRecord/Scoping/Default/ClassMethods/unscoped

For example, when trying to delete the Post object :

def destroy
  @post = Post.unscoped.find(params[:id])
  # destroy code here
end

This will search in your database without any scope.

What is the opposite of Array#reject in ruby?

• The opposite of reject is select (returning a new array)
• The opposite of reject! is select! (editing the array in place)
• The opposite of keep_if is delete_if (editing the array in place)

Opposite of joins/includes? in Rails

There's no easy way to achieve this in rails. The way I do this is to write a join in sql like the following

@business.branches
  .joins('LEFT OUTER JOIN workers ON (branches.id = workers.branch_id)')
  .where('workers.id IS NULL')

Is there an inverse 'member?' method in ruby?

Not in ruby but in ActiveSupport:

characters = ["Konata", "Kagami", "Tsukasa"]
"Konata".in?(characters) # => true

What is the difference between include and require in Ruby?

What's the difference between
"include" and "require" in Ruby?

Answer:

The include and require methods do
very different things.

The require method does what include
does in most other programming
languages: run another file. It also
tracks what you've required in the
past and won't require the same file
twice. To run another file without
this added functionality, you can use
the load method.

The include method takes all the
methods from another module and
includes them into the current module.
This is a language-level thing as
opposed to a file-level thing as with
require. The include method is the
primary way to "extend" classes with
other modules (usually referred to as
mix-ins). For example, if your class
defines the method "each", you can
include the mixin module Enumerable
and it can act as a collection. This
can be confusing as the include verb
is used very differently in other
languages.

Source

So if you just want to use a module, rather than extend it or do a mix-in, then you'll want to use require.

Oddly enough, Ruby's require is analogous to C's include, while Ruby's include is almost nothing like C's include.

Is there an opposite method of in? in Rails?

No, there is no such method. If there were, it would be defined here: https://github.com/rails/rails/blob/v6.0.2.1/activesupport/lib/active_support/core_ext/object/inclusion.rb).

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