30秒学会 JavaScript 片段 – isContainedIn

Returns true if the elements of the first array are contained in the second one regardless of order, false otherwise.

Use a for...of loop over a Set created from the first array.
Use Array.prototype.some() to check if all distinct values are contained in the second array, use Array.prototype.filter() to compare the number of occurrences of each distinct value in both arrays.
Return false if the count of any element is greater in the first array than the second one, true otherwise.

代码片段

const isContainedIn = (a, b) => {
  for (const v of new Set(a)) {
    if (!b.some(e => e === v) || a.filter(e => e === v).length > b.filter(e => e === v).length)
      return false;
  }
  return true;
};

使用样例

isContainedIn([1, 4], [2, 4, 1]); // true