Invalid argument Supplied for foreach() Axios Laravel - laravel

Question

I have a Vue.js form and I submit the form using Axios. I'm able to save the data to my database. However, when I want to save my dynamically added input fields I get this error message...
Invalid argument supplied for foreach
The problem is that it's not an array but it should be. As you can see, I would like to send the teams[] array from the Vue component to the Laravel backend with Axios. When i console.log() teams [object object], [object object].
app.js
new Vue({
el: '#regapp',
data: {
username: '',
email: '',
password: '',
password_confirmation: '',
teams: [
{
name: '',
role: '',
linkedin: '',
profileimg: ''
}
],
methods: {
onSubmit() {
axios.defaults.headers.common["X-CSRF-TOKEN"] = document
.querySelector('meta[name="csrf-token"]')
.getAttribute("content");
let formData = new FormData();
formData.append('username', this.username);
formData.append('email', this.email);
formData.append('password', this.password);
formData.append('password_confirmation', this.password_confirmation);
formData.append('teams', this.teams);
axios.post('register', formData)
.then(response => alert('Success'))
.catch(error => this.errors.record(error.response.data.errors));
}
}
}
});
Controller.php
protected function create(array $data)
{
$user = new User();
$user->name = $data['username'];
$user->email = $data['email'];
$user->password = Hash::make($data['password']);
$user->save();
// Here I try to loop trough teams and save each of them names into db.
if ($data['teams'][0] != NULL) {
$format = (array)$data;
foreach ($format['teams'] as $teams) { // The error is here
$team = new Team();
$team->user_id = $user->id;
$team->tmembername = $teams->name;
$team->save();
}
}
return $user;
}

Answer 1

Thanks Hassan for the help.
The problem was that this.teams is an array of objects - it just tries to convert the Object to a String, hence getting [object Object].
So i can't do this:
formData.append('teams', this.teams);
I had to:
var teammemb = JSON.stringify(this.teams);
Then:
formData.append('teams', teammemb);
On my RegisterController.php
$csapat = (json_decode($data['teams']));
if (is_array($csapat) || is_object($csapat)) {
// in this contition, foreach gonna work only array or object exist
foreach ($csapat as $teams) {
$team = new Team();
$team->ico_id = $ico->id;
$team->tmembername = $teams->name;
$team->save();
}
}
It works now.