php数组根据某键值，把相同键值的合并最终生成一个新的二维数组

 <?php
 $a=array(
     '0'=>array(
         'id'=>'1',
         'names'=>'jack',
         '0'=>'sendone'
     ),
     '1'=>array(
         'id'=>'3',
         'names'=>'tree',
         '0'=>'sendtwo'
     ),
     '2'=>array(
         'id'=>'5',
         'names'=>'apple',
         '0'=>'sendtwo'
     ),
 );

 $new=array();
 foreach($a as $k=>$v){
     $new[$v[0]][]=$v;
 }
 var_dump($new);
 /*
 array (size=2)
   'sendone' =>
     array (size=1)
       0 =>
         array (size=3)
           'id' => string '1' (length=1)
           'names' => string 'jack' (length=4)
           0 => string 'sendone' (length=7)
   'sendtwo' =>
     array (size=2)
       0 =>
         array (size=3)
           'id' => string '3' (length=1)
           'names' => string 'tree' (length=4)
           0 => string 'sendtwo' (length=7)
       1 =>
         array (size=3)
           'id' => string '5' (length=1)
           'names' => string 'apple' (length=5)
           0 => string 'sendtwo' (length=7)
 */
 ?>