Question

php数组分组问题

有这样一个数组：
Array
(
[0] => Array
(
[0] => 2015
[1] => aaaa1
)

[1] => Array
(
[0] => 2015
[1] => aaaa2
)

[2] => Array
(
[0] => 2015
[1] => aaaa3
)

[3] => Array
(
[0] => 2015
[1] => aaaa5
)

[4] => Array
(
[0] => 2015
[1] => aaaa7
)

[5] => Array
(
[0] => 2015
[1] => aaaa9
)

[6] => Array
(
[0] => 2016
[1] => aaaa51
)
)

如何操作能变成这样：
$newarray = array(
'2015'=>array(aaaa1,aaaa2,aaaa3,aaaa5,aaaa7,aaaa9),
'2016'=>array(aaaa51)
);

寻高手～～

Answer 1

$newarray = [];
foreacher($oldarray as $k=>$v){
$newarray[$v[0]][] = $v[1];
var_dump($newarray);
}