PHP arrays with array_merge and array_diff - php

Question

I have the following code
$usersarray =array();
foreach($users as $oneitem){
$usersarray[]=$oneitem->user_id;
}
print_r($usersarray);
$resultarray =array();
foreach($result as $oneitem){
$resultarray[]=$oneitem->friend_user_id;
}
$results = implode(", ",$result);
print_r($resultarray);
echo $results;
$excluded_user = array_diff($usersarray , $resultarray);
$excluded_user =implode(", ",$excluded_user); //comma separated ids of users whom you want to exclude
echo $excluded_user;
This outputs the following for $usersarray:
Array ( [0] => 1 [1] => 1 [2] => 1 [3] => 1 [4] => 1 [5] => 42 [6] => 43 [7] => 44 [8] => 45 [9] => 46 [10] => 47 [11] => 48 [12] => 49 [13] => 50 [14] => 51 [15] => 52 [16] => 53 [17] => 54 [18] => 55 [19] => 56 [20] => 57 [21] => 58 [22] => 59 [23] => 60 [24] => 61 [25] => 62 [26] => 63 [27] => 64 [28] => 65 [29] => 66 [30] => 86 [31] => 103 [32] => 121 [33] => 123 [34] => 124 [35] => 125 [36] => 143 [37] => 147 [38] => 149 [39] => 150 )
But for $resultarray I get this:
Array ( [0] => [1] => [2] => [3] => [4] => [5] => [6] => [7] => [8] => [9] => [10] => )
However when I echo $results I get: 64, 56, 53, 47, 44, 57, 43, 50, 1, 47, 59 which is the correct list of ID's.
It seems to be breaking down at the $excluded_user = array_diff($usersarray , $resultarray); stage. I suspect this is because of the format of $resultarray causing the array_diff() to not work properly.
Can anyone suggest why $resultarray is getting output like this? Or if this is even where the code is falling down.
Thanks in advance for any suggestions great appreciation.