Created 2 arrays of 10 but still failed

Question about the task

Under discussion

I'm not sure what I did here because when I print both of the smaller arrays I get "two small arrays of 10 numbers each". I'm also not sure how it is possible to meet 1, 2, & 4, and still not meet 3.

1. Create an array of 20 numbers.
2. Populate it with values from the keyboard.
3. Create two arrays of 10 numbers each.
4. Copy the large array into the two small ones: half the numbers into the first small array, and the second half into the second small array.
5. Display the second small array, each value on a new line.

Requirements:

The program must create an array of 20 integers.
The program should read 20 numbers from the keyboard for the large array.
The program must create two small arrays of 10 numbers each.
The program must copy one half of the large array into the first small array, copy the second half into the second array, and then display that array on the screen.

package com.codegym.task.task07.task0705; import java.io.BufferedReader; import java.io.InputStreamReader; /* One large array and two small ones */ public class Solution { public static void main(String[] args) throws Exception { //write your code here BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); int[] a = new int[20]; int[] a1 = new int[a.length/2]; int[] a2 = new int[a.length/2]; for (int i = 0; i<20; i++){ int r = Integer.parseInt(reader.readLine()); a[i] = r; } for (int i = 0; i<a.length; i++) { if (i < a.length/2) { a1[i] = a[i]; } else { a2[i-(a.length/2)] = a[i]; } } for (int e : a2) { System.out.println(e); } //for (int e : a1) { // System.out.println(e); //} } }

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Ryan Ceasar Borromeo

Level 7 , Makati, Philippines

28 March 2020, 06:26

package com.codegym.task.task07.task0705;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Scanner;

/*
One large array and two small ones

*/

public class Solution {
    public static void main(String[] args) throws Exception {
        //write your code here
        Scanner scanner = new Scanner(System.in);
        int num[] = new int[20];
        int firstHalf[] = new int[10];
        int secondHalf[] = new int[10];

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

            if(i < 10)
            {
                firstHalf[i] = number;
            } else
            {
                secondHalf[i -10] = number;
            }
        }

        for(int arr : secondHalf){
            System.out.println(arr);
        }
    }
}

Turner

Level 11 , Pittsburgh, United States

15 August 2019, 18:05

I have solved this puzzle 7 different ways but I am still unable to meet 3rd task requirement. I have updated the code to what I believe take the approaches of Java Poser and Ryan suggest but I am still missing some detail CodeGym requires that satisfies the previously aforementioned requirement. Help! Frustrated.

// Java Poser

Level 18 , Cincinnati, United States

23 February 2019, 04:36

I'll give you a huge hint on how to solve this. try getting the last ten numbers of the big array[20] by adding ten to it. similar to the way you declared the two short arrays up top(using arithmetic within the array brackets).

for (int x = 0; x < shortArray.length; x++) {
        shortArray[x] = twentyArray[x + 10];
 }

I hope this helps, let me know if you need me to explain more! good luck!

Ryan

Level 14 , Ashburn, United States

15 February 2019, 23:53

I was able to get my code to work by expressly giving a1 & a2 the number 10 instead of a.length/2 (although that should have worked as well).

Khurram

Level 16 , Lahore, Pakistan

17 February 2019, 17:52

i was about to ask you to try the same thing, coz otherwise the code is spot on

Sven

Level 19 , Hanover, Germany

19 July 2019, 15:18

I still don't get why this isn't working with a.length/2 instead of 10. I think a.length/2 is even better practice. It would be nice if someone could explain.

Turner

Level 11 , Pittsburgh, United States

15 August 2019, 17:55

It is probably because CodeGym expects strict compliance with requirements (a real-world condition actually!). Strict compliance makes automated unit testing (and white box testing) clear and straightforward. Unlike black-box testing, white box is only passed if every intermediate step meets the stated requirement (nevermind if it is correct or not ;)) ALONG with producing the correct result.