查找可變數量的Ruby數組的產品

Question

我期待從可變數量的數組中找到單個項目的所有組合。我如何在Ruby中執行此操作？

給定兩個數組，我可以使用Array.product這樣的：

groups = [] 
groups[0] = ["hello", "goodbye"] 
groups[1] = ["world", "everyone"] 

combinations = groups[0].product(groups[1]) 

puts combinations.inspect 
# [["hello", "world"], ["hello", "everyone"], ["goodbye", "world"], ["goodbye", "everyone"]] 

怎麼能當組包含可變數量的陣列此代碼的工作？

Answer 1

groups = [ 
    %w[hello goodbye], 
    %w[world everyone], 
    %w[here there] 
] 

combinations = groups.first.product(*groups.drop(1)) 

p combinations 
# [ 
# ["hello", "world", "here"], 
# ["hello", "world", "there"], 
# ["hello", "everyone", "here"], 
# ["hello", "everyone", "there"], 
# ["goodbye", "world", "here"], 
# ["goodbye", "world", "there"], 
# ["goodbye", "everyone", "here"], 
# ["goodbye", "everyone", "there"] 
# ]