Symmetric Triangles

package demo;
// print symmetric triangles - 2 ways

public class HelloJava {
    public static void main(String[] args) {
        int n = 6;

        // print symmetric rows using single loop
        for(int i = 1; i <= (n * 2 - 1); i++){
            if(i <= n){
                printLine(1, i);
            }else{
                printLine(1, n * 2 - i);
            }
        }

        // print symmetric rows using two separate loops
        for(int i = 1; i <= n; i++){
            printLine(1, i);
        }

        for(int i = n - 1; i >= 1; i--){
            printLine(1, i);
        }

    }

    public static void printLine(int start, int end){
        for(int i = start; i <= end; i++){
                System.out.print(i + " ");
        }

        System.out.println();
    }

}