[RESOLVED] Scanner Class with the ArrayList

Hello Java friends,

I am new to joining a site like this so let me get straight to the point. I am trying to make an ArrayList that stores the users input of the ages of their grandchildren. I have this code started but am lost from there as I can not find enough information on the web on how to accomplish this task.

Yes, I am an IT student with Java being my last class till I graduate, but this is not an actual assignment. I need to try to learn this task as i will be using a similar function in my project. The age of the grandchildren is something i made up as I seem to be missing how to store user inputs (specifically <Integers>), then to sum all the inputed ages (for right now I am just trying to show all the inputed ages as an array). I will be grateful for any and all help I receive.

CODE:
package grandchildren;

import java.util.Scanner;
import java.util.ArrayList;

public class GrandChildren
{


public static void main(String[] args)
{
Scanner in = new Scanner(System.in);

//My ArrayList (i am getting an redundant data type here)
ArrayList<Integer> childAge = new ArrayList<Integer>();

//Asks for the ages of the grand children
System.out.println("What are the ages of your grand children? ");
int age = in.nextInt();
if (age > 0)
{
childAge.add(age);
}
else
{
for(int i = 0; i <= childAge.size(); i++)
{
//I am getting an error here
System.out.println(childAge[i]);
}
}
}
}

The variable: childAge is not an array. Using array notation ([]) is an error. To access elements in an object like an ArrayList, you need to use a method. Read the API doc for the ArrayList class to see what methods might be useful to get an item from an ArrayList.

I understand that I have to use the get() method but I am having difficulties implementing this. any help would be greatly appreciated.

I have attached my modified code:

Code:

---


package grandchildren;

import java.util.Scanner;
import java.util.ArrayList;

public class GrandChildren
{

 
    public static void main(String[] args)
    {
        Scanner in = new Scanner(System.in);
       
        //My ArrayList
        ArrayList<Integer> childAge = new ArrayList<Integer>();
       
        //Asks for the ages of the grand children
        System.out.println("What are the ages of your grand children? ");
        // int age = in.nextInt();
        while(in.hasNextInt())
        {
            childAge.add(in.nextInt());
        }
       
        for(int childAge2 : childAge)  //I have tried 2 different ways
        {
            System.out.println(childAge2);
        }
        for (int i = 0; i < childAge.size(); i++)
        {
            int age = childAge.get(i);
            System.out.println(age);
        }
   
       
    }
}

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Quote:

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I am having difficulties

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Please explain. If there are error messages, copy the fill text and paste it here.


Please edit your post and wrap your code with code tags:
[code]
YOUR CODE HERE
[/code]
to get highlighting and preserve formatting.

I am not getting an error this time....... I can not get it to print the inputed ArrayList. If I input a series of integers (1 2 3 for example), it does not print out 1 2 3.

Can you copy the contents of the window from when you execute the program and paste it here to show what you are talking about.
The code works for me. I get the following output:
1
2
3
1
2
3

This is what I get in my console window:
run:
What are the ages of your grand children?
1 2 3
BUILD SUCCESSFUL (total time: 12 seconds)

The 1 2 3 is what I put in, but I don't receive any output.

The Scanner class's method is waiting for more input. You need a way to tell it that the input is finished.

One possible solution: End the input with a non-digit like this: 1 2 3 X

What would be an acceptable way to terminate or exit the scanner? Given this section of code

Code:

---

    while(in.hasNextInt())
            {
              childAge.add(in.nextInt());
            }
       
            for (int element : childAge)
            {
                System.out.print(element);
            }

---

I am trying to either use "X" or 0 as the exit qualifier.

Any non-numeric value which will cause the hasNextInt() method to return false will end the while() loop. When you ask the user for his input, you need to tell him how to end it. It's up to you how to tell him what to enter.

I have it figured out... Thanks for everything and all the advise.

Code:

---

package grandchildren;

import java.util.Scanner;
import java.util.ArrayList;

public class GrandChildren
{

 
    public static void main(String[] args)
    {
        Scanner in = new Scanner(System.in);
       
     
        ArrayList<Integer> childAge = new ArrayList<Integer>();
        int age = 0;
     
        System.out.println("What are the ages of your grand children? (Enter any letter value to exit)");
     
            while(in.hasNextInt())
            {
                age = in.nextInt();
                if (age >= 1)
                        {
                            childAge.add(age);
                        }
                else{System.out.println("That is an invalid input.");}
            }
        System.out.println(childAge);

---