迭代一个数组的数组，查找另一个数组中的匹配项

function findMatchingItems(arr1, arr2) {
  var result = [];

  for (var i = 0; i < arr1.length; i++) {
    for (var j = 0; j < arr1[i].length; j++) {
      if (arr2.includes(arr1[i][j])) {
        result.push(arr1[i][j]);
      }
    }
  }

  return result;
}

// 示例用法
var arr1 = [[1, 2, 3], [4, 5, 6], [7, 8, 9]];
var arr2 = [2, 5, 8];
var matchingItems = findMatchingItems(arr1, arr2);
console.log(matchingItems); // 输出 [2, 5, 8]