我的程序旨在从.txt文件中读取相册信息,一旦用户输入所需的轨道,程序就会检查一个数组以查看它是否包含该轨道。我已成功地将轨道读入数组,但我的程序无法识别字符串是否位于此数组中。
Ruby文件
require './input_functions'
module Genre
POP, CLASSIC, JAZZ, ROCK = *1..4
end
$genre_names = ['Null', 'Pop', 'Classic', 'Jazz', 'Rock']
class Album
attr_accessor :title, :artist, :genre, :tracks
def initialize (title, artist, genre)
# insert lines here
@title = title
@artist = artist
@genre = genre
end
end
class Track
attr_accessor :name, :location
def initialize (name, location)
@name = name
@location = location
end
end
def read_track(music_file)
track_name = music_file.gets
track_location = music_file.gets
track = Track.new(track_name, track_location)
end
def read_tracks(music_file)
tracks = Array.new
count = music_file.gets.to_i
index = 0
while index < count
tracks << read_track(music_file)
index += 1
end
tracks
end
def print_tracks(tracks)
index = 0
while (index < tracks.length)
puts 'Track Number ' + index.to_s + ' is:'
print_track(tracks[index])
index = index + 1
end
tracks
end
def read_album music_file
album_artist = music_file.gets
album_title = music_file.gets
album_genre = music_file.gets
album = Album.new(album_title, album_artist, album_genre)
album
end
def print_album album
puts 'Album title is ' + album.title.to_s
puts 'Album artist is ' + album.artist.to_s
puts 'Genre is ' + album.genre.to_s
puts $genre_names[album.genre.to_i]
# print out the tracks
puts 'Tracks are ' + print_tracks(album.tracks).to_s
end
def print_track track
puts('Track title is: ' + track.name.to_s)
puts('Track file location is: ' + track.location.to_s)
end
** This is where I am having my problem
# search for track by name.
# Returns the index of the track or -1 if not found
def search_for_track_name(tracks, search_string)
search_string = gets.chomp
index = 0
while (index < tracks.length)
tracks.include?(search_string)
index = index + 1
end
if tracks.include?(search_string)
return index
else
index = -1
end
return index
end
# Reads in an Album from a file and then prints all the album
# to the terminal
def main
music_file = File.new("album.txt", "r")
if music_file
album = read_album(music_file)
album.tracks = read_tracks(music_file)
music_file.close()
end
search_string = read_string("Enter the track name you wish to find: ")
index = search_for_track_name(album.tracks, search_string)
if index.to_i > -1
puts "Found " + album.tracks[index].name + " at " + index.to_s
else
puts "Entry not Found"
end
print_album(album)
end
main
这是.txt文件
Neil Diamond
Greatest Hits
1
3
Crackling Rose
sounds/01-Cracklin-rose.wav
Soolaimon
sounds/06-Soolaimon.wav
Sweet Caroline
sounds/20-Sweet_Caroline.wav
当用户输入“Sweet Caroline”时,程序应返回已找到该轨道的信息,而不是:
Enter the track name you wish to find:
Sweet Caroline
Entry not Found
Album title is Greatest Hits
Album artist is Neil Diamond
Genre is 1
Pop
Track Number 0 is:
Track title is: Crackling Rose
Track file location is: sounds/01-Cracklin-rose.wav
Track Number 1 is:
Track title is: Soolaimon
Track file location is: sounds/06-Soolaimon.wav
Track Number 2 is:
Track title is: Sweet Caroline
Track file location is: sounds/20-Sweet_Caroline.wav
Tracks are [#<Track:0x000000000331be58 @name="Crackling Rose\n", @location="sounds/01-Cracklin-rose.wav\n">, #<Track:0x000000000331bdb8 @name="Soolaimon\n", @location="sounds/06-Soolaimon.wav\n">, #<Track:0x000000000331bd18 @name="Sweet Caroline\n", @location="sounds/20-Sweet_Caroline.wav\n">]
你的问题是album.tracks
是Track
对象的数组。
而你试图像album.tracks.include?(search_string)
一样检查它。当然,不包括在内。
所以你的index = -1
和"Entry not Found"
。
您可以使用而不是if tracks.include?(search_string)
if tracks.map(&:name).include?(search_string)
但是你还需要解决另一个问题:你的轨道中的名字现在最终有\n
。
所以你需要的不是track_name = music_file.gets
track_name = music_file.gets.chomp
希望这会有所帮助。