如何对数组内的整数求和？

Question

a = [[5, 6], [6, 5], [7, 4], [1, 0, 0], [9, 9], [6, 8], [8, 6], [1, 8, 0], [9, 0]]

如何对内部数组中的整数求和并返回内部数组之和的数组？

我需要它返回[(5+6), (6+5), (7+4), (1+0+0), ...]，因此[11, 11, 11, 1, 18, 14, 14, 9, 9]

Answer 1

a.map{|a| a.inject(:+)}
# => [11, 11, 11, 1, 18, 14, 14, 9, 9]

Answer 2

尝试

a.map { |a| a.reduce(:+) }

然后sum_arry = a.map { |sub_arry| sub_arry.inject(&:+) } 应该是您想要的数组。

Answer 3

使用// Get a list of posts starred ... databaseReference.child("users").child(getUid()).child(starred); // Iterate through and get value of `author` and `post` ... // Store the values in variables var author = "..."; var post = "..."; // Make the call return databaseReference.child("posts").child(post); + map

reduce