将一个数组的所有对象按键加入同一个数组

let arr = [{"n1":{"0":"2"},"f1":{"0":3}},{"n1":{"1":"3"},"f1":{"1":2}}]

let modified = arr.reduce((res, objs) => {
  for (let key in objs) {
    res[key] = res[key] || {}
    for (let i in objs[key]) {
      res[key][i] = objs[key][i]
    }
  }
  return res
}, {})

let result = [modified]

console.log(result)

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