二维数组分组

/**
 * 二维数组分组
 * @param  [type] $arr [二维数组]
 * @param  [type] $key [键名]
 * @return [type]      [新的二维数组]
 */
public function arrayGroupBy($arr, $key){
    $grouped = array();
    foreach ($arr as $value) {
        $grouped[$value[$key]][] = $value;
    }
    if (func_num_args() > 2) {
        $args = func_get_args();
        foreach ($grouped as $key => $value) {
            $parms = array_merge($value, array_slice($args, 2, func_num_args()));
            $grouped[$key] = call_user_func_array('array_group_by', $parms);
        }
    }
    return $grouped;
}

分组前数据格式：

array:5 [
  0 => array:22 [
    "name" => "Jackie Ma8"
    "avatar" => "http://fooku.oss-cn-hongkong.aliyuncs.com/Content/UserHeadImage/2018-04-05/Thumbnail/b6d97aa1-1a90-42fd-80f2-1e33e41d808a.png"
    "last_company" => "广州陪我公司"
    "last_position" => "前端工程师"
    "job_type" => "风控专员"
    "channel" => "boss直聘"
  ]
  1 => array:22 [
    "name" => "Jackie Ma9"
    "avatar" => "http://fooku.oss-cn-hongkong.aliyuncs.com/Content/UserHeadImage/2018-04-05/Thumbnail/b6d97aa1-1a90-42fd-80f2-1e33e41d808a.png"
    "last_company" => "广州陪我公司"
    "last_position" => "前端工程师"
    "job_type" => "风控专员"
    "channel" => "boss直聘"
  ]
  2 => array:22 [
    "name" => "Jackie Ma10"
    "avatar" => "http://fooku.oss-cn-hongkong.aliyuncs.com/Content/UserHeadImage/2018-12-26/Thumbnail/5b4dc79d-81a1-494b-b2a5-be8164635ab3.png"
    "last_company" => "广州优才有限公司"
    "last_position" => "客服"
    "job_type" => "财务薪酬统计"
    "channel" => "智联招聘"
  ]
  3 => array:22 [
    "name" => "Jackie Ma12"
    "avatar" => "http://fooku.oss-cn-hongkong.aliyuncs.com/Content/UserHeadImage/2018-12-26/Thumbnail/5b4dc79d-81a1-494b-b2a5-be8164635ab3.png"
    "last_company" => "广州优才有限公司"
    "last_position" => "客服"
    "job_type" => "财务薪酬统计"
    "channel" => "智联招聘"
  ]
  4 => array:22 [
    "name" => "Jackie Ma11"
    "avatar" => "http://fooku.oss-cn-hongkong.aliyuncs.com/Content/UserHeadImage/2018-12-26/Thumbnail/5b4dc79d-81a1-494b-b2a5-be8164635ab3.png"
    "last_company" => "广州优才有限公司"
    "last_position" => "客服"
    "job_type" => "财务薪酬统计"
    "channel" => "智联招聘"
  ]
]

分组后数据格式：

array:2 [
  "boss直聘" => array:2 [
    0 => array:22 [
      "name" => "Jackie Ma8"
      "avatar" => "http://fooku.oss-cn-hongkong.aliyuncs.com/Content/UserHeadImage/2018-04-05/Thumbnail/b6d97aa1-1a90-42fd-80f2-1e33e41d808a.png"
      "last_company" => "广州陪我公司"
      "last_position" => "前端工程师"
      "job_type" => "风控专员"
      "channel" => "boss直聘"
    ]
    1 => array:22 [
      "name" => "Jackie Ma9"
      "avatar" => "http://fooku.oss-cn-hongkong.aliyuncs.com/Content/UserHeadImage/2018-04-05/Thumbnail/b6d97aa1-1a90-42fd-80f2-1e33e41d808a.png"
      "last_company" => "广州陪我公司"
      "last_position" => "前端工程师"
      "job_type" => "风控专员"
      "channel" => "boss直聘"
    ]
  ]
  "智联招聘" => array:3 [
    0 => array:22 [
      "name" => "Jackie Ma10"
      "avatar" => "http://fooku.oss-cn-hongkong.aliyuncs.com/Content/UserHeadImage/2018-12-26/Thumbnail/5b4dc79d-81a1-494b-b2a5-be8164635ab3.png"
      "last_company" => "广州优才有限公司"
      "last_position" => "客服"
      "job_type" => "财务薪酬统计"
      "channel" => "智联招聘"
    ]
    1 => array:22 [
      "name" => "Jackie Ma12"
      "avatar" => "http://fooku.oss-cn-hongkong.aliyuncs.com/Content/UserHeadImage/2018-12-26/Thumbnail/5b4dc79d-81a1-494b-b2a5-be8164635ab3.png"
      "last_company" => "广州优才有限公司"
      "last_position" => "客服"
      "job_type" => "财务薪酬统计"
      "channel" => "智联招聘"
    ]
    2 => array:22 [
      "name" => "Jackie Ma11"
      "avatar" => "http://fooku.oss-cn-hongkong.aliyuncs.com/Content/UserHeadImage/2018-12-26/Thumbnail/5b4dc79d-81a1-494b-b2a5-be8164635ab3.png"
      "last_company" => "广州优才有限公司"
      "last_position" => "客服"
      "job_type" => "财务薪酬统计"
      "channel" => "智联招聘"
    ]
  ]
]