Javascript - 按索引对数组的每个元素求和

Question

我有一个JavaScript数组：

var array1 = [ [1, 2, 3], [7, 9, 2], [6, 8, 1] ]

我希望输出为：

var array2 = [ 14, 19, 6 ]

array1[0] = 1 + 7 + 6
array1[1] = 2 + 9 + 8
array1[2] = 3 + 2 + 1

如何通过索引对数组的每个元素求和？

Answer 1

你可以试试这个：

var array1 = [ [1, 2, 3], [7, 9, 2], [6, 8, 1] ]
var array2 = [ [4, 5, 6], [2, 6, 12], [10, 10, 10] ]


function sumByIndex(arr) {
    return arr.map( (item, idx) => {
        return arr.reduce( (prev, curr) => prev + curr[idx] , 0 )
    })
}


sumByIndex(array1)
//[ 14, 19, 6 ]


sumByIndex(array2)
//[ 16, 21, 28 ]