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"      }    }  }