PHP Creating Nested Array Dynamically

Question

I am having trouble on how can I get the result of the nested array, it shows only one data per Branch, it should be show all Division per Branch.

$selectedBranches = ['1', '5'];
$selectedDivisions = ['1', '3', '5', '26', '27'];

$branch = \App\Branch::whereIn('BranchID', $selectedBranches)->get();
$division = \App\Division::whereIn('DivisionID', $selectedDivisions)->get();

for ($b = 0; $b < count($selectedBranches); $b++) {
    for ($c = 0; $c < count($selectedDivisions); $c++) {
        if ($branch[$b]->BranchID == $division[$c]->BranchID) {
            $branch_arr[$branch[$b]->BranchID] = array(
                $division[$c]->DivisionName
            );
        }
    }
}

Branch Query Result

BranchID	BranchName
1	BranchOne
5	BranchFive

Division Query Result

DivisionID	DivisionName	BranchID
1	Foo	1
3	Fooz	1
5	Rap	1
26	Bar	5
27	Barz	5

Output

^ array:2 [▼
  1 => array:1 [▶
    0 => "Foo"
  ]
  5 => array:1 [▶
    0 => "Bar"
  ]
]

Expected Output

^ array:5 [▼
  1 => array:1 [▶
    0 => "Foo",
    1 => "Fooz",
    2 => "Rap",
  ]
  5 => array:1 [▶
    0 => "Bar",
    1 => "Barz",
  ]
]

Answer 1

    $branch_arr = [];
    for ($b = 0; $b < count($selectedBranches); $b++) {
    $branch_arr[$branch[$b]['BranchID']] = [];
    for ($c = 0; $c < count($selectedDivisions); $c++) {
        if ($branch[$b]['BranchID'] == $division[$c]['BranchID']) {
            $branch_arr[$branch[$b]['BranchID']][] = array(
                $division[$c]['DivisionName']
            );
        }
    }
}