We can also insert new elements into an ArrayList.
To insert new elements into an ArrayList, we can use a slightly different version of the add method that you previously used:
ArrayList<Integer> quizGrades = new ArrayList<Integer>();
quizGrades.add(95);
quizGrades.add(87);
quizGrades.add(73);
quizGrades.add(0, 100);
System.out.println( quizGrades.get(0) );
The example above will print out the grade 100.
The add method will insert the grade 100 at the first position (0) into the list. Since it inserts a new element into the beginning of the ArrayList, all other element indices will be shifted one position higher. The grade 95 is now at index 1.