프로그래머스 - 행렬의 곱셈

function solution(arr1, arr2) {
    return Array(arr1.length).fill('').map(
        (rowValue, index) => Array(arr2[0].length).fill('').map(
            (verticalValue, innerIndex) => arr1[index].reduce(
                (target, current, array) =>target + current * arr2[array][innerIndex], 0
            )
        )
    )
}