ary.each { |e| ... }
ary.each_index { |i| ... }
ary.each_with_index { |e, i| ... } # e是数组元素,i是该元素对应的下标
ary.map { |e| ... }
ary.collect { |e| ... }
ary.inject([]) { |result, element| ... }
ary1.zip(ary2, ary3) # 将数组中下标相同的元素组成一个数组,并将这些数组作为新数组的元素返回,该数组的元素个数取决与ary1的元素个数(与之相等)
1 a = [ 4, 5, 6 ] 2 b = [ 7, 8, 9 ] 3 [1,2,3].zip(a, b) #=> [[1, 4, 7], [2, 5, 8], [3, 6, 9]] 4 [1,2].zip(a,b) #=> [[1, 4, 7], [2, 5, 8]] 5 a.zip([1,2],[8]) #=> [[4,1,8], [5,2,nil], [6,nil,nil]]