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javainputarraylist

ArrayList input java


I'm looking at the problem:

Write a program which reads a sequence of integers and displays them in ascending order.

I'm creating an ArrayList (which I am new to) and I want to populate with integers input from the command line. With an array I could use a for loop with:

for (int i =0; i < array.length; i++) {
    array[i] = scanner.nextInt();

but with an ArrayList of unbounded size I'm not sure how to process the input.

EDIT:

class SortNumbers {

    public static void main(String[] args) {
        List numbers = new ArrayList();
        Scanner scanner = new Scanner(System.in);
        System.out.println("Enter some numbers.");
        while (scanner.hasNextInt()) {
            int i = scanner.nextInt();
            numbers.add(i);
        }
    }
}

Solution

  • The idea with using ArrayList is to avoid the deterministic iteration counts. Try something like this:

    ArrayList<Integer> mylist = new ArrayList<Integer>();
    while (sc.hasNextInt()) {
        int i = sc.nextInt();
        mylist.add(i);
    }