Nested For Loop Trouble?

Question

Ok I need to have a nested for loop that asks a user to enter in a int number from 1-50. Whatever the number is, lets say 4 I need the program to count up asterisk and count down asterisks, like this.
This is my code:
import java.io.*;
public class Stars {
     static int n;
     static private InputStreamReader in = new InputStreamReader(System.in);
     static private BufferedReader br = new BufferedReader(in);
     public static void main(String[] Args)throws IOException
          System.out.println("Please enter in a number to see display: ");
          String num = br.readLine();
          n=Integer.parseInt(num);
          for(int i=1;i<=n;i++)
               for(int j=1;j<=i;j++)
                    System.out.print("*");
               for(int j=1;j<=i;j--)
                    System.out.print("*");
               System.out.println();
Can someone tell me what I am doing wrong so I can figure out my mistake(s).

Answer 1

Ok, well I know that the loop relies on the number entered in by the user. So if i pick 3 the three enter in the loop and counts up in a for loop and for every number it counts up to the three it does a print("*"); Now what I am getting confused about is where the other for loop comes into play. I know that I need to start from the number I have which is 3, so I need to have one less than that and then count down. The thing is that i'm not sure where or how the second for loop gets implemented into the code. Does it get nested with the first loop like this:
for(int i=1;i<=n;i++)
               for(int j=1;j<=i;j++)
                        for(int j=n-1;j>=i;j--)
                    System.out.print("*");
               System.out.println();
          }Or is the second for loop on its own like this:
for(int i=1;i<=n;i++)
               for(int j=1;j<=i;j++)
                    System.out.print("*");
               for(int j=n-1;j>=i;j--)
                    System.out.print("*");
               System.out.println();
          }If someone can help me understand, for this is my first time with nested for loops.