Today I Learned

Def keyword can also be used as a begin statement

In Ruby, the begin keyword for exception handling (ie, begin...rescue...ensure, traditionally try...catch...finally in other languages) is optional. You can have a method that only declares a rescue or an ensure statement without begin. That's because the def statement in the method can serve the same purpose as begin. This means that this method:

def edit
  begin
    @user = find(params[:id])
    ...
  rescue ActiveRecord::RecordNotFound
    redirect_to :back
  end
end

Can legally be shortened to:

def edit
  @user = find(params[:id])
  ...
rescue ActiveRecord::RecordNotFound
  redirect_to :back
end