CODEWITHSUNDEEP
ruby-on-railsarraysrubyhash
James Mitchell
James Mitchell

Reputation: 2467

How to access first item in hash value array

I have a hash whose value is an array of song lyrics (line1, line2, etc..)

Code:

class Song
    def initialize(lyrics)
       @lyrics = lyrics 
    end
    def get_song_name()
        puts @lyrics.keys
    end
    def get_first_line()
        puts @lyrics.values[0]
    end
end

wasted = Song.new({"Wasted" => ["I like us better when we're wasted",
    "It makes it easier to see"]})

real_world = Song.new("Real World" => ["Straight up what do you want to learn about here", "if i was someone else would this all fall apart"])

wasted.get_song_name()
wasted.get_first_line()
#=>I like us better when we're wasted
#=>It makes it easuer to see

So when I called wasted.get_first_line, I want it to get the first item in the array of the value. I tried doing @lyrics.values[0], but it returns both lines of the song instead of the first one.

How do I accomplish this?

Upvotes: 7

Views: 8613

Answers (3)

Wand Maker
Wand Maker

Reputation: 18762

This is not the answer to original question, but if I were you, I would modify the class like below. It will be more apt to store song name and lines of lyrics as individual attributes, instead of merging them as a hash - which kind of defies the whole purpose of having Song class.

class Song
    attr_accessor :song_name, :lyrics

    def initialize(song_name, lyrics)
       @song_name = song_name
       @lyrics = lyrics 
    end
end

Please note that you may not need get_first_line method. You could always use Array#first to have same effect:

real_world = Song.new("Real World", ["Line 1", "Line 2"])
puts real_world.lyrics.first # Prints "Line 1"

You can also access lyrics lines using array index

puts real_world.lyrics[1] # Prints "Line 2"

Upvotes: 3

ndnenkov
ndnenkov

Reputation: 36100

Lets use this hash for example:

x = {foo: [:bar, :baz]}

x.values             # => [[:bar, :baz]]
x.values.first       # => [:bar, :baz]
x.values.first.first # => :bar

In other words, @lyrics.values[0] will return the first value in the @lyrics hash, which is the array of two songs. You still have to get the first song out of that array.

Upvotes: 3

shivam
shivam

Reputation: 16506

You need to understand that in the above code @lyrics is a Hash. Here is what you are doing and what it translates to:

@lyrics
# => {"Wasted"=>["I like us better when we're wasted", "It makes it easier to see"]} 


@lyrics.values
# => [["I like us better when we're wasted", "It makes it easier to see"]] 

@lyrics.values[0]
# => ["I like us better when we're wasted", "It makes it easier to see"] 

@lyrics.values[0][0]

# => "I like us better when we're wasted"

Therefore to access the first line, you need to get the first element of the values array. i.e.

@lyrics.values[0][0]

or

@lyrics.values.first.first

Upvotes: 13

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