php - Laravel 5.4 add a message to validator's errors -

so receiving data form should reset user passwords:
old password: |field|
new password: |field|
confirm password: |field|
, want able display message out user if old password not match entered in first field. don't want make entirely new validation method , want throw error use when make own if(). how achieve using $errors variable available in blade views

so here example of controllers method

public function update(request $request){     $this->validate($request,[         'oldpassword' => 'required',         'password' => 'required|min:8|confirmed'     ]);     $user = auth::user();     if(password_verify($request->newpass,$user->password)){          $user = user::find($user->id);          $user->password = bcrypt($request->newpass);          $user->save();     }else{          //the code adding new key $errors variable          return back(); or return redirect('path');     } } 

so in view want

@if (count($errors) > 0) <div class="alert alert-danger">     <ul>         @foreach ($errors->all() $error)             <li>{{ $error }}</li>         @endforeach     </ul> </div> @endif 

you can in controller:

$validator =  validator::make($request->all(),[     'oldpassword' => 'required',     'password' => 'required|min:8|confirmed' ]); 

and before return back();, add:

$validator->after(function($validator) {     $validator->errors()->add('tagname', 'error message'); }); 

with message.