學習Ruby - 卡在數組中的字符串比較

Question

我正在學習通過Ruby進行學習編程，而且我堅持構建自己的排序方法。

我竭力要弄清楚爲什麼我的recursive_sort裏面的比較方法是拋出了一個錯誤

chapter10.rb:120:in `block in recursive_sort': undefined method `<' for ["zebra"]:Array (NoMethodError) 

但是，這只是正常工作...

lowest = 'zebra' 
if 'cat' < 'zebra' 
    lowest = 'cat' 
end 
puts lowest 

能幫有人在正確的方向，可以幫助我把我的頭圍繞這個？謝謝！

puts 'Sorting Program with recursion v1.0' 

# Keep two more lists around 
# One for already-sorted words 
# One for still - unsorted words 
# Find the smallest word in the unsorted list 
# push it into the end of the sorted_array 

def sort some_array 
    recursive_sort some_array, [] 
end 

def recursive_sort unsorted_array, sorted_array 
    lowest = unsorted_array[0] 
    unsorted_array.each do |uns| 
     if uns < lowest 
      lowest = uns 
     end 
    end 
    puts lowest 
end 

# Get a list of unsorted words into an array 
orig_array = [] 
word = 'placeholder' 
puts 'Enter a list of words to be sorted. Press enter when done.' 
while word != '' 
    word = gets.chomp 
    orig_array.push [word] 
end 
orig_array.pop 

puts 'This is the output of the built in sort method.' 
orig_array.sort.each do |un| 
    puts un 
end 

puts 'This is the output of Rick\'s sort method.' 
sort orig_array 

Answer 1

orig_array.push [word] 

在這裏，你實際上是在推動一個數組的數組，這樣你的orig_array成爲

[["word 1"], ["word 2"], ["word 3"], ...] 

取出[]周圍word來解決這個問題，或者改變.push到+=或.concat，它將兩個陣列粘合在一起。