fungsi.php

// fungsi ganti password
	public function gantipassword($tabel, $password_lama, $password_baru, $where){
      try{
         $query = $this->db->prepare("SELECT * FROM $tabel WHERE password = :password_lama OR username = :username");
         $query->execute(array(":password_lama" => $password_lama, ":username" => $where));

         $data = $query->fetch();

         if ($data) { // jika ada data di database, maka :
           if (password_verify($password_lama, $data['password'])) { // jika password yang di hash cocok, maka :

             $hashpass = password_hash($password_baru, PASSWORD_DEFAULT); // hash password yang diganti

             // edit password lama menjadi password baru berdasarkan user
             $update = $this->db->prepare("UPDATE $tabel SET password = :password_baru WHERE username = :username");
             $update->execute(array(":password_baru" => $hashpass, ":username" => $where));

             echo '<div class="alert alert-success" role="alert">Password berhasil di ubah. </div>';
           }else{
             echo '<div class="alert alert-danger" role="alert">Password lama tidak cocok. Coba lagi</div>';
           }
         }

      }catch(PDOexception $e){
        echo $e->getMessage();
      }
    }