js扁平化数组

[javascript]代码库

const flatten = (arr) => {
  return arr.reduce((prev, curr) => {
    return Array.isArray(curr) ? prev.concat(flatten(curr)) : prev.concat(curr);
  }, []);
}
const arr1 = [1, [2, [3, 4]], 5];
const arr2 = flatten(arr1);
console.log(arr2); // [1, 2, 3, 4, 5]