如何在数组数组中添加值？

Question

I have an array of arrays with four integer elements like this:

arrays = [[a1,b1,c1,d1],[a2,b2,c2,d2],[a3,b3,c3,d3]] 

I want to add these three arrays. The result should be in one array like:

result = [a1+a2+a3,b1+b2+b3,c1+c2+c3,d1+d2+d3]

I tried but not able to do this.

Answer 1

>> arrays = [[1,2,3,4],[2,3,4,5],[3,4,5,6]]
=> [[1, 2, 3, 4], [2, 3, 4, 5], [3, 4, 5, 6]]
>> arrays.transpose.map { |xs| xs.inject :+ }
=> [6, 9, 12, 15]

Answer 2

由于您使用的是Rails，因此可以使用：

arrays.transpose.map &:sum

Answer 3

Here's a quick example:

a = [1, 2, 3] 
b = [4, 5, 6] 
c = [7, 8, 9]

[a, b, c].transpose.map { |x| x.reduce :+ } 

=> [12, 15, 18]

For further clarification see " Some Array magic using transpose, map and reduce ".