Need to generate Asterisks into a Triangle!

Question

Hey there.
I'm having a bit of trouble progressing with my Uni work, i've been here for weeks trying to suss it. Unfortunately I am not very good when it comes to Java and I'm struggling like hell.
What i need to do is write a public instance method called toString() which takes no arguements. The method should return a string which is made up by concatenating strings of asterisks, which are separated by the new line character. If the instance variable orientation references the string "up" the strings should be of ever increasing lengthfrom 1 up to the value of the instance variable size. If the instance variable orientation references the string "down" the strings should be of ever decreasing lengthfrom the value of the size down to 1.
Note that the method must return the string object it has constructed. It should not output it either to a dialogue box or by using System.out.println(). You should use a loop to construct the string that has to be returned; each iteration should involve adding an extra row of asterisks to the string by using concatenation.
Further up in the code, I have the following:
public class Triangle
   /* instance variables */
   int size; // the size of the triangle; an integer between 2 and 10 inclusive
   String orientation; // either "up" or "down"
    * Constructor for objects of class Triangle.
   public Triangle()
      super();
      this.size = 5;
      this.orientation = "up";
   }And here is my failed attempt at the code:
public String toString(){
String aResult;
if(orientation == "up"){
String asterisk = "*";
for(int b=0; b<size; b++){
aResult = asterisk + System.getProperty("line.separator") + asterisk + System.getProperty("line.separator");
return aResult;
}Any help or a shove in the right direction would be a greatly appreciated!
Kind Regards
Thanks

Answer 1

Here's how you could do it (see the comments in the toString() method):
public class Triangle {
    private int size;
    private boolean up;
    public Triangle(int s, boolean u) {
        size = s;
        up = u;
    public String toString() {
        StringBuilder b = new StringBuilder();
        loop from 1 to 'size'
            'numAsterisks' <- what should this be when 'up'==tue?
                              and what should it be when 'up'==false?
            loop from 1 to 'numAsterisks'
                append an asterisk to 'b'
            end loop
            append an new line to 'b'
        end loop
        return b.toString();
    public static void main(String[] args) {
        Triangle t = new Triangle(5, true);
        System.out.println(t);
}