將一個數組的每個元素連接到ruby中其他數組的每個元素

Question

我有兩個數組，我可以連接它們循環這兩個數組。但是有沒有更好的方法來做到這一點？

需要

colors = ['yellow', 'green'] 
shirts = ['s','m','xl','xxl'] 

輸出：

output = ['yellow_s','yellow_m','yellow_xl','yellow_xxl','green_s','green_m','green_x','green_xxl'] 

Answer 1

使用Array#product，你可以得到笛卡爾乘積：

colors = ['yellow', 'green'] 
shirts = ['s','m','xl','xxl'] 
colors.product(shirts).map { |c, s| "#{c}_#{s}" } 
# => ["yellow_s", "yellow_m", "yellow_xl", "yellow_xxl", 
#  "green_s", "green_m", "green_xl", "green_xxl"] 

colors.product(shirts).map { |e| e.join("_") } 
# => ["yellow_s", "yellow_m", "yellow_xl", "yellow_xxl", 
#  "green_s", "green_m", "green_xl", "green_xxl"] 

Answer 2

我用這個方法。

colors = ['green', 'yellow'] 
shirts = ['s','m', 'xl', 'l'] 
selection = [] 
x = 0 
while x < shirts.length 
    selections.push(colors.map{|c|c + "_" + shirts[x]}) 
    x += 1 
end 
selections.flatten! 

=> ['yellow_s', 'green_s', 'yellow_m', 'green_m', 'yellow_xl', 'green_xl', 'yellow_xxl', 'green_xxl']