IndexOutOfBounds Exception ArrayList Loop

Question

I am doing a school task on ArrayLists and Wrapper classes. I have to initialize a for loop, which should fill the ArrayList up with the numbers 1 to 99.

ArrayList<Integer> list = new ArrayList<Integer>();
for(int i = 1; i < 100; i++){
   list.add(i);
   System.out.println(list.get(i));
}

The code until the for-loop body is given in the task.

If I run the code, I get an IndexOutOfBounds Exception.

What can I modify to be able to run the loop?

score 2 · Accepted Answer · answered Jun 27 '20 at 05:15

2

Indexes of list start from 0. So your elements would be from 0 - 99 and not from 1 - 100. access them using list.get(i-1)

answered Jun 27 '20 at 05:15

Ghost

735
5
16

score 1 · Answer 2 · edited Jun 27 '20 at 17:08

1

Modify your code as System.out.println(list.get(i-1)); because index start from 0.

edited Jun 27 '20 at 17:08

h3t1

1,126
2
18
29

answered Jun 27 '20 at 05:22

ravikj17

9
1

score 1 · Answer 3 · answered Jun 27 '20 at 05:48

An array begins always with the index 0. In almost every languages

ArrayList<Integer> list = new ArrayList<Integer>();
for(int i = 1; i < 100; i++){
   list.add(i);
   System.out.println(list.get(i-1));
}

or

ArrayList<Integer> list = new ArrayList<Integer>();
for(int i = 0; i < 99; i++){
   list.add(i+1);
   System.out.println(list.get(i));
}

IndexOutOfBounds Exception ArrayList Loop

3 Answers3