Decision problem within an array loop

Question

My problem is in the second if, what I was actually trying to do was to determine that at the time the loop was passing through position 11 of the array it would add the " n", but the way I did it, it does it in all loops, not just in the position I want. I understand my mistake, but I don’t know how to do it properly.

  package gerarOrganizar;
  import java.util.*;
  //import java.util.Arrays;
  //import java.util.Collections;
  //import java.util.Random;
  import static javax.swing.JOptionPane.*;
  public class GerarOrganizar {


    public static void main(String[] args) {
        Integer[] array = new Integer[20];
        Random gerador=new Random();
        String aux="";
        for(int i=0;i<20;i++){
            array[i]=gerador.nextInt(50);
            if(array[i]==0)//descarta números = 0
                i--;
        }//for de geração de valores

        aux=String.format("Antes \n");
        for(int i:array){//percorre todo o array retornando o valor para i
            if(array[11]!=null)//este aqui é o problema
                aux=String.format(aux+"\n");
            aux=String.format(aux+"\t %d",i);
    }//fim do for

        showMessageDialog(null,aux);//imprime a ordem gerada

        Arrays.sort(array,Collections.reverseOrder());
        /*sort decide a ordem númerica em ordem decrescente devido ao Collections.reverseOrder*/

        aux=String.format("Depois");
            for(int i:array){/*percorre array retornando os valores para i*/
                aux=String.format(aux+"\n %d",i);/*copia os valor do array na string*/
            }//fim do for

        showMessageDialog(null,aux);//imprime a ordem
    }//main

 }//class

Answer 1

This is because in all interactions in the cycle in question position 11 in the vector is different from null.

You can solve it like this:

...
for(int i; i<array.lenght; i++){//percorre todo o array retornando o valor para i
   if( i == 11 ){
         aux=String.format(aux+"\n");
   }
   aux=String.format(aux+"\t %d",array[i]);
}//fim do for
...