regex - Ruby method undefined for nilClass errors for string methods -


i don't understand why below doesn't work:

#todo: #open file-io-samples/multiplelinescustomdelimiter.txt #break each line fields #convert times mm:ss seconds #remove redundant spaces. #######################################################  song = struct.new(:title, :name, :length)  file.open("file-io-samples/multiplelinescustomdelimiter.txt") |file_data|   songs = []   file_data.each |line|     file, length, name, title =  line.chomp.split(/\s*\|\s*/)     name.squeeze!(" ") #error: undefined method nilclass     mins, secs = length.scan(/\d+/) #error: undefined method nilclass     secs += mins*60     songs << song.new(title, name, secs)   end   puts songs[1] #make sure output consistent. end

contents of file that's being read:

/jazz/j00132.mp3 | 3:45 | fats waller | ain't misbehavin' /jazz/j00319.mp3 | 2:58 | louis armstrong | wonderful world /bgrass/bg0732.mp3| 4:09 | strength in numbers | texas red : : : :

this example programming ruby book. dont know why scan method , squeeze method throw errors when string objects not nilclass objects. without these output puts songs[1] looks correct.

the last row

: : : :

doesn't match split, name, length , title nil

file ends

: : : :

a parallel example:

a,b,c = [1,2] #a=1 #b=2 #c = nil

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