Why do I always get undefined value from other data? - ajax

Question

I always get undefined values from other data for example: ID:123 the response for this would be the NetAmount: 1000.00 after sending it using AJAX GET REQUEST, so for other data it would just return an undefined value.
MY AJAX
function viewBill(AccountNum){
$.ajaxSetup({
headers: {
'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
}
});
$.ajax({
method: "GET",
url: "{{ route('view.billing') }}",
data: {AccountNum:AccountNum},
dataType: 'json',
async: true,
beforeSend: function() {$('#userBill').html('Getting Information...')},
success: function(res) {
console.log(res.NetAmount);
$('#checkBill').css('display','block');
$('#userBill').html('₱ '+res.NetAmount);
},
error: function(res) {console.log('Error');},
complete: function() {
}
});
}
My Controller
public function viewBilling(Request $request){
if($request->ajax()){
$viewBilling = Table1::addSelect(['PaymentStatus' => Table2::selectRaw('COUNT(*)')
->whereColumn('AccountNumber','Table1.AccountNumber')
->whereColumn('ServicePeriodEnd','Table1.ServicePeriodEnd')
->where('AccountNumber', $request->AccountNum)
])->where('AccountNumber', $request->AccountNum)
->orderBy('ServicePeriod','desc')
->first();
return Response()->json($viewBilling);
}
}
I tried using dd() and it turns out there are values for the account I tried from the one that returns the NetAmount and from the one that returns an undefined value.

Answer 1

Found the problem, because of the parameter of my viewBill() function, I don't know why would it give me undefined values from other data I did check using the network tools, it just that it wasn't able to send the AccountNumber to the Controller. So I tried removing the parameter. I have an input tag that already has the value of the Account Number so instead of using the above code, I did this
function viewBill(){
var AccountNum = $('#inputAccountNum1').val();
$.ajaxSetup({
headers: {
'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
}
});
$.post({
url: "{{ route('view.billing') }}",
data: {AccountNum:AccountNum},
dataType: 'json',
beforeSend: function() {$('#userBill').html('Getting Information...')},
success: function(res) {
$('#checkBill').css('display','block');
$('#userBill').html('₱ '+res.NetAmount);
},
error: function(res) {console.log('Error');},
complete: function() {
}
});
}