[Ruby] Level 2 Methods and Classes

Optional Arguments

Set default arguments, when we don ' t need to call it, we can simply skip it.

def new_game (name, Year=nil, system=nil)  {    name:name,    year:year,    system:system  = New_game ("Street figher II")

Options Hash Argument

Sometimes, optinal argumetns also not good. For exmaple, we had one argument added to the end, if we did want pass in reply_id and year, system we don ' t need to pass In, then we need-put placeholder in the function call.

def new_game (name, Year=nil, system=nil, reply_id = nil)  {    name:name,    year:year,    system : System  = New_game ("Street figher II", nil, nil, 50)

Therefore We can use options have argument:

def new_game (name, options={})  {    name:name,    year:options[:year],    system: Options[:system]  = New_game ("Street figher II",  1992 ,   " SNES ")

Exception

def get_tweet (list)    unless list.authorized? ( @user)        raise  authorizationexception.new    end    list.tweetsend#  Raise an Exception insteadbegin         = get_tweets (my_list) Rescue Authorizationexception     "You is not a authorized to access the Thislist"end

[Ruby] Level 2 Methods and Classes