"Solving Problems" PHP multidimensional array sorting problem

Recently touched PHP, just encountered a problem, involving the problem of multi-dimensional array sorting. The array has a key PID, which requires the array to be rearranged again by PID. Just sort the first-level array. Array_multisort () was used, but an error occurred. As follows:

Array ([0] = = Array ([PID] = 0 [Title] = home [path] = Index            [Current] = 0 [link] =/index.php) [1] = = Array ([tid] = 3 [PID] = 8 [Mid] = 8 [Topid] = 0 [upid] + 0 [Exmid]                 + 0 [LinkId] + 2 [gotoid] = [LNG] = cn [Larray] = = Array                            ([0] = = Array ([tid] = 17 [PID] [Mid] = 8 [topid] = =                        3 [Upid] = 3) [1] = = Array ([Tid] = [PID] = [mid               ] = 8             [Topid] = 3 [upid] + 3) [2] =&G T                            Array ([tid] = + [PID] = 50                        [Mid] = 8 [Topid] = 3 [Upid] + 3 ))) [2] = = Array ([tid] = 5 [PID] =&gt ; 2 [Mid] = 3 [Topid] = 0 [Upid] = 0 [Exmid] + 0 [lar Ray] = Array ([0] = = Array ([                            TID] = [PID] = [Mid] = 3                      [Topid] = 5 [Upid] = 5) [1] = = Array  ([Tid] = [PID] = [Mid] =                    > 3 [Topid] = 5 [upid] 5)                            [2] = = Array ([tid] = 22                            [PID] = [Mid] = 8 [Topid] + 5  [Upid] + 5)) [3] = = Array ([tid] = = [PID] = 4 [Mid] = 8 [Topid] = 0 [Upid] = 0 [lar Ray] =))

The end result is as follows: The PID was rearranged from small to large.

Array ([0] = = Array ([PID] = 0 [Title] = home [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] = [PID] = [Mid] = 3                    [Topid] + 5 [upid] = 5) [1] = = Array ([tid] = [PID] = > [Mid] = 3 [Topid] = 5 [Up             ID] = 5           ) [2] = = Array ([tid] = 22                            [PID] = [Mid] = 8 [Topid] + 5            [Upid] + 5))) [2] = = Array (  [Tid] = [PID] = 4 [Mid] = 8 [topid] + 0 [upid] = =            0 [Larray] + =) [3] = = Array ([tid] = 3 [PID] + 8 [Mid] = 8 [Topid] = 0 [Upid] = 0 [Exmid] + 0 [LinkId] =& Gt                    2 [gotoid] = [LNG] = cn [Larray] = = Array ( [0] = = Array ([tid] = + [PID] =&G T               50             [Mid] = 8 [Topid] = 3 [Upid] + 3                            ) [1] = = Array ([tid] = 18                            [PID] = [Mid] = 8 [Topid] + 3                        [Upid] = 3) [2] = = Array ([Tid] = [PID] + [Mid] =                > 8 [Topid] = 3 [upid] 3) )        )   )

Reply to discussion (solution)

It is recommended to post an array of Var_export () to test

And so the master, I will only choose the sort

Set the original array to $ar, there is

Array_multisort (Array_map (function ($item) {return $item [' pid '];}, $ar), $ar);

It is recommended to post an array of Var_export () to test
This is what print_r printed out.

It is recommended to post an array of Var_export () to test

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