Assignment for internship interview using Android Studio. The task was to pass an array from one activity to another. In the first activity, have a button which loads the second activity and displays a list of the array data passed from the first.

Here is how I approached this problem:

1. Create a string array called interns and populate it with data.
2. Create a new activity called ListActivity which will display the array data in a ListView.
3. Make a ListView in activity_list.xml and give it the id internList.
4. Pass array interns from MainActivity to ListActivity using an Intent intentListActivity and the putExtra() intent method.
5. Add attribute android:onClick="openListActivity" to ButtonView on MainActivity so that the method openListActivity runs and opens ListActivity when tapped.
6. In ListActivity, collect interns array from MainActivity with getIntent().getStringArrayExtra("interns") and store in local string array called interns.
7. Next, find a ListView to attach interns data to by using findViewById() method and setting to internListView.
8. Create array adapter internsAdapter to map array data to ListView.
9. Set internsAdapter to internListView with setAdapter() method.

Originally, when I first made/committed this code, it did not display the array data in the ListActivity. In fact, the application crashed upon running it. After submission, I found that this was because I used the incorrect method to extract the data passed from the MainActivity. Instead of using getStringArrayExtra("interns"), I mistakenly used getStringArrayListExtra("interns"), which caused a null-object error in Android Studio.

This was not compatible with the putExtra() method on the intentListActivity intent I created in MainActivity. Another option might have been to use putStringArrayListExtra() on the intent instead to pass the data to ListActivity.