How to create a array with "n" random integers?

Question

Create two Integer ArrayLists containing n ​elements each where n​​ will be taken from the user.

so basically if a user inputs '6' two arrays with 6 elements needs to be created. How would I do this?

This is what I have.. but its not even remotely correct.

Scanner input= new Scanner(System.in);
    System.out.println("please enter a integer 'n' ");
    int x= input.nextInt();

    int[] a = { 1, 4, 9, 16 };
    int[] b = { 9, 7, 4, 9, 11 };

Answer 1

If you want to generate random integer array from an interval, here are the options

// generate 100 random number between 0 to 100 
int[]  randomIntsArray = IntStream.generate(() -> new Random().nextInt(100)).limit(100).toArray();
//generate 100 random number between 100 to 200
int[]  randomIntsArray = IntStream.generate(() -> new Random().nextInt(100) + 100).limit(100).toArray();

Answer 2

You can take input from the user by using a scanner like this -

Scanner input= new Scanner(System.in);
System.out.println("Enter the array size: ");
int n = input.nextInt(); 

Now create a function generateRandomArray(int n) like this -

public List<Integer> generateRandomArray(int n){
    ArrayList<Integer> list = new ArrayList<Integer>(n);
    Random random = new Random();
    
    for (int i = 0; i < n; i++)
    {
        list.add(random.nextInt(1000));
    }
   return list;
}  

Here - random.nextInt(1000) will generate a random number from the range 0 to 1000. You can fix the range as you want.

Now you can call the function with the value n get from the user -

ArrayList<Integer> list1 = generateRandomArray(n);
ArrayList<Integer> list2 = generateRandomArray(n);

Hope it will help.