js 数字平铺flat的实现

function flat(arr, count) {

if(count === 0) {

return arr

}

return arr.reduce((data, next) => {

if(Array.isArray(next)) {

return data.concat(flat(next, count - 1))

} else {

return data.concat(next)

}

}, [])

}

let flatArr = [1, 2, [3, 4, [5, 6]],[7, 8, [9, 12, 13, [88, 99]]]]

let res = flat(flatArr, 1)

console.log(res)