how to take user input in Array using java?

Question

how to take user input in Array using Java? i.e we are not initializing it by ourself in our program but the user is going to give its value.. please guide!!

Answer 1

Here's a simple code that reads strings from stdin, adds them into List<String>, and then uses toArray to convert it to String[] (if you really need to work with arrays).

import java.util.*;

public class UserInput {
    public static void main(String[] args) {
        List<String> list = new ArrayList<String>();
        Scanner stdin = new Scanner(System.in);

        do {
            System.out.println("Current list is " + list);
            System.out.println("Add more? (y/n)");
            if (stdin.next().startsWith("y")) {
                System.out.println("Enter : ");
                list.add(stdin.next());
            } else {
                break;
            }
        } while (true);
        stdin.close();
        System.out.println("List is " + list);
        String[] arr = list.toArray(new String[0]);
        System.out.println("Array is " + Arrays.toString(arr));
    }
}

---

See also:

• Why is it preferred to use Lists instead of Arrays in Java?
• Fill a array with List data

Answer 2

package userinput;

import java.util.Scanner;

public class USERINPUT {

    public static void main(String[] args) {

        Scanner input = new Scanner(System.in);

        //allow user  input;
        System.out.println("How many numbers do you want to enter?");
        int num = input.nextInt();

        int array[] = new int[num];

        System.out.println("Enter the " + num + " numbers now.");

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

        //you notice that now the elements have been stored in the array .. array[]

        System.out.println("These are the numbers you have entered.");
        printArray(array);

        input.close();

    }

    //this method prints the elements in an array......
    //if this case is true, then that's enough to prove to you that the user input has  //been stored in an array!!!!!!!
    public static void printArray(int arr[]){

        int n = arr.length;

        for (int i = 0; i < n; i++) {
            System.out.print(arr[i] + " ");
        }
    }

}