[1, 2, 3, 4].reduce((x, y) => console.log(x, y))A: 1 2 and 3 3 and 6 4
B: 1 2 and 2 3 and 3 4
C: 1 undefined and 2 undefined and 3 undefined and 4 undefined
D: 1 2 and undefined 3 and undefined 4 参考答案:
[1, 2, 3, 4].reduce((x, y) => console.log(x, y))A: 1 2 and 3 3 and 6 4
B: 1 2 and 2 3 and 3 4
C: 1 undefined and 2 undefined and 3 undefined and 4 undefined
D: 1 2 and undefined 3 and undefined 4 参考答案: