[Solution] PHP multi-dimensional array sorting

[Problem solving] PHP multi-dimensional array sorting recently encountered a problem involving multi-dimensional array sorting. Each array of this series has a key PID, which requires that the array be rearranged according to the PID. Just sort the first layer of array. Array_multisort () is used, but an error is returned. As follows:

Array ([0] => Array ([pid] => 0 [title] => homepage [path] => index [current] => 0 [link] =>/index. php) [1] => Array ([tid] => 3 [pid] => 8 [mid] => 8 [topid] => 0 [upid] => 0 [exmid] => 0 [linkid] => 2 [gotoid] => 17 [lng] => cn [larray] => Array ([0] => Array ([tid] => 17 [pid] => 50 [mid] => 8 [topid] => 3 [upid] => 3) [1] => Array ([tid] => 18 [pid] => 50 [mid] => 8 [topid] => 3 [upid] => 3) [2] => Array ([tid] => 19 [pid] => 50 [mid] => 8 [topid] => 3 [upid] => 3 ))) [2] => Array ([tid] => 5 [pid] => 2 [mid] => 3 [topid] => 0 [upid] => 0 [exmid] => 0 [larray] => Array ([0] => Array ([tid] => 11 [pid] => 50 [mid] => 3 [topid] => 5 [upid] => 5) [1] => Array ([tid] => 12 [pid] => 50 [mid] => 3 [topid] => 5 [upid] => 5) [2] => Array ([tid] => 22 [pid] => 50 [mid] => 8 [topid] => 5 [upid] => 5 ))) [3] => Array ([tid] => 50 [pid] => 4 [mid] => 8 [topid] => 0 [upid] => 0 [larray] => ))

The final result is as follows: the PID is rearranged from small to large.

Array ([0] => Array ([pid] => 0 [title] => homepage [path] => index [current] => 0 [link] =>/index. php) [1] => Array ([tid] => 5 [pid] => 2 [mid] => 3 [topid] => 0 [upid] => 0 [exmid] => 0 [larray] => Array ([0] => Array ([tid] => 11 [pid] => 50 [mid] => 3 [topid] => 5 [upid] => 5) [1] => Array ([tid] => 12 [pid] => 50 [mid] => 3 [topid] => 5 [upid] => 5) [2] => Array ([tid] => 22 [pid] => 50 [mid] => 8 [topid] => 5 [upid] => 5 ))) [2] => Array ([tid] => 50 [pid] => 4 [mid] => 8 [topid] => 0 [upid] => 0 [larray] =>) [3] => Array ([tid] => 3 [pid] => 8 [mid] => 8 [topid] => 0 [upid] => 0 [exmid] => 0 [linkid] => 2 [gotoid] => 17 [lng] => cn [larray] => Array ([0] => Array ([tid] => 17 [pid] => 50 [mid] => 8 [topid] => 3 [upid] => 3) [1] => Array ([tid] => 18 [pid] => 50 [mid] => 8 [topid] => 3 [upid] => 3) [2] => Array ([tid] => 19 [pid] => 50 [mid] => 8 [topid] => 3 [upid] => 3 ))))

Reply to discussion (solution)

We recommend that you paste the array after var_export (); for testing.

And other experts, I will only choose to sort

If the original array is set to $ ar

array_multisort(array_map(function($item){ return $item['pid']; }, $ar), $ar);

We recommend that you paste the array after var_export (); for testing.
This is printed by print_r.

We recommend that you paste the array after var_export (); for testing.