使用简单的暴力算法找出数组中最大的4个元素

function findLargestFourElements(arr) {
  if (arr.length < 4) {
    return "数组长度小于4";
  }
  
  var largestFour = [arr[0], arr[1], arr[2], arr[3]];
  largestFour.sort(function(a, b) {
    return b - a;
  });
  
  for (var i = 4; i < arr.length; i++) {
    if (arr[i] > largestFour[3]) {
      largestFour[3] = arr[i];
      largestFour.sort(function(a, b) {
        return b - a;
      });
    }
  }
  
  return largestFour;
}

var arr = [1, 5, 3, 9, 7, 2, 8, 6, 4];
console.log(findLargestFourElements(arr));