1.ES6的flat
const arr = [1, [2, 3, [4, 5]]]
arr.flat(Infinity)
2.递归
const arr = [1, [2, 3, [4, 5]]]
const flat = (arr) => {
let result = []
for (let i = 0, len = arr.length; i < len; i++ ) {
Array.isArray(arr[i]) ? result = [...result, ...flat(arr[i])] : result.push(arr[i])
}
return result
}
flat(arr)
3.reduce + 递归
const arr = [1, [2, 3, [4, 5]]]
const flat = (arr) => {
if (!Array.isArray(arr)) return
return arr.reduce((prev, curr) => prev.concat(Array.isArray(curr) ? flat(curr) : curr), [])
}
flat(arr)
4.扩展运算符 + 迭代
const arr = [1, [2, 3, [4, 5]]]
const flat = (arr) => {
while(arr.some((item) => Array.isArray(item))) {
arr = [].concat(...arr)
}
return arr
}
flat(arr)
5.序列化 + 正则
const arr = [1, [2, 3, [4, 5]]]
const flat = (arr) => {
return JSON.parse(`[${JSON.stringify(arr).replace(/(\[|\])/g, '')}]`)
}
flat(arr)