public IHttpActionResult DeleteSubjectFromStudent(string id, int subjectId) { if (studentsService.ExistsID(id) == false || subjectsService.ExistsID(subjectId) == false) { return(NotFound()); } if (studentsService.StudentHasSubject(id, subjectId) == false) { return(BadRequest("Student does not have that subject in his/hers subject list")); } return(Ok(studentsService.DeleteSubjectFromStudent(id, subjectId))); }