[Ruby] LEVEL 2 Methods and Classes

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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  }endgame = new_game("Street Figher II")

 

Options Hash Argument

Sometimes, optinal argumetns also not that good. For exmaple, we have one argument added to the end, if we do want pass in reply_id and year, system we don‘t need to pass in, then we need to put placeholder in the function call.

def new_game(name, year=nil, system=nil, reply_id = nil)  {    name: name,    year: year,    system: system  }endgame = new_game("Street Figher II", nil, nil, 50)

Therefore we can use options has argument:

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

 

Exception

def get_tweet(list)    unless list.authorized?(@user)        raise AuthorizationException.new    end    list.tweetsend#raise an Exception insteadbegin         tweets = get_tweets(my_list)rescue AuthorizationException    warn "You are not authorized to access this list"end

 

[Ruby] LEVEL 2 Methods and Classes