Array 操作

一、数组拉平

function arrayFlat(arr) {
  return arr.reduce((pre, cur) => {
    const temp = Array.isArray(cur) ? arrayFlat(cur) : cur;
    return pre.concat(temp);
  }, []);
}
const result = arrayFlat([1, [2, 3], [4, [5, 6, [8]], 7]]);
console.log(result);

// 数组拉平 es6 flat
// const arr = [1, [2, 3], [4, [5, 6, [8]], 7]];
// // console.log(arr.flat());
// console.log(arr.flat(2));
// console.log(arr.flat(3));
// [1, [2, [3]]].flat(Infinity);

 二、打乱数组

// 方法1
function ArrayBreak1(arr) {
  const $arr = [...arr];
  return $arr.sort(() => Math.random() - 0.5);
}

console.log(ArrayBreak1([1, 2, 3, 4, 5, 6]));

// 方法2
function ArrayBreak2(arr) {
  const $arr = [...arr];
  const result = [];
  while ($arr.length) {
    const index = Math.floor(Math.random() * $arr.length);
    result.push($arr[index]);
    $arr.splice(index, 1);
  }
  return result;
}

console.log(ArrayBreak2([1, 2, 3, 4, 5, 6]));