Вывод верный, но не проходит по условию

public static int[] firstArray = new int[]{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
   public static int[] secondArray = new int[]{10, 11, 12, 13, 14, 15, 16, 17, 18, 19};
   public static int[] resultArray;

   public static void main(String[] args) {
       resultArray = new int[firstArray.length + secondArray.length];
       for (int i = 0; i < resultArray.length; i++) {
            for (int j = 0; j < firstArray.length; j++)
               {
                      resultArray[j] = firstArray[j];
               }
             for (int g = 0; g < secondArray.length; g++)
               {
                      resultArray[g + firstArray.length] = secondArray[g];
               }
           System.out.print(resultArray[i] + ", ");
       }
   }

package com.javarush.task.pro.task05.task0504;

/*
Объединяем массивы
*/

import java.util.Arrays;

public class Solution {
    public static int[] firstArray = new int[]{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
    public static int[] secondArray = new int[]{10, 11, 12, 13, 14, 15, 16, 17, 18, 19};
    public static int[] resultArray;

    public static void main(String[] args) {
        int[] resultArray = new int[firstArray.length + secondArray.length];
        for (int i = 0; i < resultArray.length; i++) {
            if (i < firstArray.length) {
                resultArray[i] = firstArray[i];
            } else {
                resultArray[i] = secondArray[i - firstArray.length];
            }
            System.out.print(resultArray[i] + ", ");
        }
        doSomething();
    }

    public static void doSomething() {
        System.out.println("\nмассив, записанный в переменной класса:  " + Arrays.toString(resultArray));

    }
}