php多个数组根据指定键值分组方法

php多个数组根据指定键值分组方法：

$array：要分组的数组

$key：根据的键名

function array_group($array,$key)
{
$result = [];
foreach($array as $k=>$v){
  $result[$v[$key]][] = $v;
}
return $result;
}

演示数组：

$arr = [
[
  'city' => 'beijing',
  'name' => '大哥'
],
[
  'city' => 'shanghai',
  'name' => '二哥'
],
   [
  'city' => 'guangzhou',
  'name' => '三哥'
],
   [
  'city' => 'beijing',
  'name' => '四哥'
]
];

调用方法：

var_dump(array_group($arr,'city'));

输出数组：

array(3) {
  ["beijing"] => array(2) {
    [0] => array(2) {
      ["city"] => string(7) "beijing"
      ["name"] => string(6) "大哥"
    }
    [1] => array(2) {
      ["city"] => string(7) "beijing"
      ["name"] => string(6) "四哥"
    }
  }
  ["shanghai"] => array(1) {
    [0] => array(2) {
      ["city"] => string(8) "shanghai"
      ["name"] => string(6) "二哥"
    }
  }
  ["guangzhou"] => array(1) {
    [0] => array(2) {
      ["city"] => string(9) "guangzhou"
      ["name"] => string(6) "三哥"
    }
  }
}