Creating a Christmas Tree using for loops

Try this much simpler code:

public class ChristmasTree {

 public static void main(String[] args) {

  for (int i = 0; i < 10; i++) {
   for (int j = 0; j < 10 - i; j++)
    System.out.print(" ");
   for (int k = 0; k < (2 * i + 1); k++)
    System.out.print("*");
   System.out.println();
  }
 }
}

It uses 3 loops:

• first one for the number of rows,
• second one for printing the spaces,
• third one for printing the asterisks.

You can do it with simple logic

for (int i = 0; i < 4; i++) 
            System.out.println("   *******".substring(i, 4 + 2*i));