Compare multidimensional array with string php

If have a array.I want to compare my array value with a string .

here i have a value $uid=something.

if my array item objectId is same with $uid then those element goes to new array .

    Array
    (
        [results] => Array
            (
                [0] => Array
                    (
                        [birthday] => 11-Apr-2014
                        [category] => Array
                            (
                                [0] => 204
                                [1] => 300
                                [2] => 304
                            )

                        [city] => fgfg
                        [country] => fgf
                        [email] => [email protected]
                        [fullName] => fg
                        [gender] => Male
                        [inspirational] => Run to dream
                        [phone] => gfg
                        [photo] => Array
                            (
                                [__type] => File
                                [name] => 8bef9bc3-ee64-45df-9698-0466e255c1bd-profilePhoto.jpg
                                [url] => http://files.com/c2dcf728-e2a3-4b2d-a8c8-6ec9b3c6502a/8bef9bc3-ee64-45df-9698-0466e255c1bd-profilePhoto.jpg
                            )

                        [username] => aapbd
                        [website] => http://aahgh.com
                        [createdAt] => 2014-04-10T19:01:16.396Z
                        [updatedAt] => 2014-04-28T07:36:18.459Z
                        [objectId] => IQSCdXE2hI
                    )

                [1] => Array
                    (
                        [birthday] => 09-Apr-1982
                        [category] => Array
                            (
                                [0] => 204
                                [1] => 307
                                [2] => 311
                                [3] => 313
                                [4] => 102
                                [5] => 103
                                [6] => 105
                                [7] => 107
                            )

                        [city] => Madrid
                        [country] => Spain
                        [coverPhoto] => Array
                            (
                                [__type] => File
                                [name] => aa53cf65-47af-464d-aa49-88202f91388f-coverPhoto.jpg
                                [url] => http://files.com/c2dcf728-e2a3-4b2d-a8c8-6ec9b3c6502a/aa53cf65-47af-464d-aa49-88202f91388f-coverPhoto.jpg
                            )

                        [description] => a lazy man
                        [email] => [email protected]
                        [fullName] => Shghghossain
                        [gender] => Male
                        [inspirational] => Honesty is the best policy
                        [phone] => 135469
                        [photo] => Array
                            (
                                [__type] => File
                                [name] => a1aec283-f3c7-484c-a8b2-a0b09c5f3023-profilePhoto.jpg
                                [url] => http://files.com/c2dcf728-e2a3-4b2d-a8c8-6ec9b3c6502a/a1aec283-f3c7-484c-a8b2-a0b09c5f3023-profilePhoto.jpg
                            )

                        [username] => asa
                        [website] => 
                        [createdAt] => 2014-04-09T07:58:19.043Z
                        [updatedAt] => 2014-05-07T11:13:40.671Z
                        [objectId] => iVb6olefaT
                    )

        )

)

I use this code but not work

$ids2 =array();
foreach($array_post['results'] AS $i)
{
$ids ='iVb6olefaT';

        if(in_array($i['objectId']==$ids))
        {
        $ids2[]=$i;


         }
         else
         {
         $ids2;
         }
}