查找数组中每个数组的平均值

function findAverage(arr) {
  var result = [];
  
  for (var i = 0; i < arr.length; i++) {
    var sum = 0;
    for (var j = 0; j < arr[i].length; j++) {
      sum += arr[i][j];
    }
    var average = sum / arr[i].length;
    result.push(average);
  }
  
  return result;
}

// 示例用法
var array = [[1, 2, 3], [4, 5, 6], [7, 8, 9]];
var averages = findAverage(array);
console.log(averages); // 输出 [2, 5, 8]