How to solved Invalid argument supplied for foreach() - laravel

Question

I am tired to solve the problem. I will see that everything is ok. but maybe there is any wrong. why that showing Invalid argument supplied for foreach(). What is wrong here? Please solved it.
<form action="{{route('send.email.noactiveusers')}}" method="post">
#csrf
<div class="form-group row">
<label class="col-form-label col-lg-2">To All No Active users</label>
<div class="col-lg-10">
<select multiple="multiple" class="form-control select" name="noactivemail" data-fouc>
<optgroup label="Subscribed users">
#foreach($client as $val)
#if($val->NoActivities($val->last_deposit)==="yes")
<option value="{{$val->email}}" selected>{{$val->email}}</option>
#else
#endif
#endforeach
</optgroup>
</select>
</div>
</div>
<div class="form-group row">
<label class="col-form-label col-lg-2">Subject:</label>
<div class="col-lg-10">
<input type="text" name="subject" maxlength="200" value="No activities for over 3 months"
class="form-control">
</div>
</div>
<div class="form-group row">
<label class="col-form-label col-lg-2">Message:</label>
<div class="col-lg-10">
<textarea type="text" name="message" rows="4" class="form-control tinymce">We see that no activities over 3 months on your account. If you want to stay active in your account then please deposit on your account within 7 days. Otherwise, your account deactivated.</textarea>
</div>
</div>
<div class="text-right">
<button type="submit" class="btn bg-dark">Send<i class="icon-paperplane ml-2"></i></button>
</div>
</form>
public function SendEmailtoNoActiveUsers(Request $request)
{
$set=Settings::first();
foreach ($request->noactivemail as $email) {
$user=User::whereEmail($email)->first();
send_email($user->email, $user->name, $request->subject, $request->message);
}
return back()->with('success', 'Message sent!.');
}

Answer 1

you are using multiple select but you are not using an array to send those selected values. when you are sending multiple values with the same name attribute you have to make it an array. so just update your select with
<select multiple="multiple" class="form-control select" name="noactivemail[]" data-foucs>
this will send an array named noactivemail with your form request. and you can then iterate in the controller.
foreach ($request->noactivemail as $email) {
$user = User::where('email', $email)->first();
send_email($user->email, $user->name, $request->subject, $request->message);
}