Clearing arraylist also clears object arraylist

Asked Dec 06 '17 at 03:57

Active Dec 06 '17 at 04:01

Viewed 84 times

So basically I have code that looks like this

supersetRowModel.setExerciseModelList(exerciseModelList);
exerciseModelList.clear();

My getter and setter for this class

 public void setExerciseModelList(List<ExerciseModel> exerciseModelList){
    this.exerciseModelList = exerciseModelList;
}

public List<ExerciseModel> getExerciseModelList(){
    return exerciseModelList;
}

Whenever I call getExerciseModelList() right after I clear the array list, it returns a list with size 0. I have checked and made sure that exerciseModelList is not size 0. This is confusing me, since clearing exerciseModelList should not affect the objects arraylist since it is already set, right?

asked Dec 06 '17 at 03:57

Gerald Tan

Just do `exerciseModelList = new ArrayList<>();` instead of clearing it. – shmosel Dec 06 '17 at 04:03
Works, thanks. But why wouldn't my method work? – Gerald Tan Dec 06 '17 at 04:07
Because your assumption is wrong. Both references are pointing to the same list. – shmosel Dec 06 '17 at 04:08
That makes sense now. – Gerald Tan Dec 06 '17 at 04:11

Clearing arraylist also clears object arraylist

0 Answers0