Insert multiple data with many to many relationship in laravel - laravel-5

Question

I have four models with many to many relationship
Users
-id
-Email
-Password
Student
-id
-Name
-school
---------
Subject
-id
-subname
Topic
-id
-topName
-sub_id
--------
When they broke down produce their respective pivot tables
i.e
-student_user
-id
-student_id
-user_id
-student_subject
-id
-studdent_id
-subject_id
-subject_name
-student_topic
-id
-student_id
-topic-id
-topic_name
-.........
I want to insert them with multiple selecting of the inputs i.e subject and topics must more than one.
What i failed is how to insert them into a data at the same time with such kind of relation since i used for each loop and i failed to figure out what attribute i can use to??
Topics and subjects datas are insided DB inserted already
Help
<table class="table table-striped" id="table_tuition_fee">
<thead>
<tr>
<td><label for="subject">Subject</label></td>
<td><label for="topic">Topic</label></td>
<td><label for="Amount">Amount</label></td>
<td><a class="bg-light btn btn-info addRow" href="#"><i class="fa fa-plus"></i></a></td>
</tr>
</thead>
<tbody>
<tr>
<td>
<select class="form-control subject_selected" name="subject[]" id="subject" data-uid="0">
<option value=" ">---Select Subject---</option>
#foreach($subject_list as $subject)
<option value="{{ $subject->id }}">{{ $subject->SubjectName }}</option>
#endforeach
</select>
</td>
<td>
<select class="form-control topic_selected" name="topic[]" id="topic" data-uid="0">
</select>
</td>
<td>
<input type="text" class="form-control" name="Amount[]" id="Amount"/>
</td>
<td>
X
</td>
</tr>
</tbody>
<tfoot>
<tr>
<td style="border: none"></td>
<td style="border: none"></td>
<td style="border: none"></td>
<td><button class="btn btn-success" id="add_student">SEND</button></td>
</tr>
</tfoot>
</table
class Topic extends Model
{
//
protected $fillable = [
'TopicName'.'Subject_id'
];
public function students(){
return $this->belongsToMany(Student::class)->withTimestamps();
}
public function subject(){
return $this->belongsTo(Subject::class);
}
}
class User extends Authenticatable
{
use Notifiable ,HasRoles;
/**
* The attributes that are mass assignable.
*
* #var array
*/
protected $fillable = [
'FullName'.'EmployeeNumber','password',
];
.
.
.
.
.
public function buyers(){
return $this->belongsToMany(Buyer::class)->withTimestamps();
}
public function students(){
return $this->belongsToMany(User::class)->withTimestamps();
}
}
class Student extends Model
{
//
protected $fillable = [
'FullName'.'School','Combination','Phone','Type','Stream'
];
public function users(){
return $this->belongsToMany(User::class)->withTimestamps();
}
public function subjects(){
return $this->belongsToMany(Subject::class)->withTimestamps();
}
public function topics(){
return $this->belongsToMany(Topic::class)->withTimestamps();
}
}
class Subject extends Model
{
protected $fillable = [
'SubjectName',
];
public function students(){
return $this->belongsToMany(Student::class)->withTimestamps();
}
public function topics(){
return $this->hasMany(Topic::class);
}
}
public function store(Request $request)
{
/*$this->validate($request,[
'FullName' => 'requred|string',
]);*/
$student = new Student();
$student->FullName = $request->input('FullName');
.
.
.
.;
$id = $student->save();
//$user = User::find(auth()->user()->id);
if ($id != 0){
$condition = $request->input('subject');
/*$student->subjects()->create([
'subject_name'=>$request->input('subject')
]);*/
foreach ( $condition as $key => $av){
$data =array([
'subject_id' => $request->input('subject')[$key],
'subject_name' => $request->input('subject')[$key],
'topic_name' => $request->input('topic')[$key],
'Price' => $request->input('Amount')[$key]
]);
$student->subjects()->attach($data);
}
}
return Response()->json($student);
}

Answer 1

I made it my self as follows
public function store(Request $request)
{
$student = new Student();
$student->FullName = $request->input('FullName');
.
.
.
$student->Stream = $request->input('Stream');
$id = $student->save();
if ($id != 0){
$condition = $request->subject; //ACCESS SUBJECT NAME ARRAY subject[]
$condition1 = $request->topic; //ACCESS SUBJECT NAME ARRAY topic[]
foreach ( $condition as $key => $av){
$data =array([
'subject_id' => $request->subject[$key]
]);
$student->subjects()->attach($data);
}
foreach ( $condition1 as $key_topic => $av_topic){
$data2 = array([
'topic_id' => $request->topic[$key_topic],
'Price' => $request->Amount [$key_topic]
]);
$student->topics()->attach($data2);
}
$student->users()->attach(auth()->user()->id);
}
$status = 'Failed To Register' ;
if($student){
$status = 'Student Successfully Added';
}
return redirect()->back()->with('status' ,$status);
}