CODEWITHSUNDEEP
javagenericsbinary-search-tree
alexthefourth
alexthefourth

Reputation: 137

Java Generics Test class

Im new to generics and i have to implement a binary search tree using generics. I did that but now im wondering how do i test the code that i wrote? Do i just make another class and start using the methods of the bst?

any help would be appreciated. below is my code just to clarify.

public class BST<E extends Comparable<E>>
{
public Node<E> root;


public BST()
{
    root = null;
}
//insert delete find height
public void find(E s, Node<E> n)
{
    //empty tree, root is null
    if(n == null)
    {
        System.out.println("Item not present.");
    }
    //n is the node where s is, return n
    else if(n.getData().equals(s))
    {
        System.out.println("Item present");
    }
    //s is greater than n, look for s on the right subtree
    else if(s.compareTo(n.getData()) > 0)
    {
        find(s, n.getRight());
    }
    //s is less than n, look for s on the left subtree
    else
    {
        find(s, n.getLeft());
    }
}

public int height() 
{
    int count;
    return count = height(root); 
}

private int height(Node<E> n)
{
    int ct = 0;
    if(n == null)
    {

    }

    else
    {

        int left = height(n.getLeft());

        int right = height(n.getRight());

        ct = Math.max(left, right) + 1;
    }
    return ct;
} 

public void insert(E s) 
{
    root = insert(s, root);
} 

private Node<E> insert(E s, Node<E> T)
{
    //easiest case, empty tree, create new tree
    if(T == null)
    {
        T = new Node<E>(s,null,null);
    }
    //easiest case, found s
    else if(s.compareTo(T.getData()) == 0)
    {
        System.out.println("Item already present.");
    }
    //s is greater than T, insert on right subtree
    else if(s.compareTo(T.getData()) > 0)
    {
        T.setRight(insert(s, T.getRight()));
    }
    //s is less than T, insert on left subtree
    else
    {
        T.setLeft(insert(s,T.getLeft()));
    }
    return T;
}

public void delete(E d)
{
}

}

and my node class

public class Node<E> 
{
   private E data;
private Node<E> left;
private Node<E> right;
private Node<E> parent;

   public  Node(E d, Node<E> r, Node<E> l) 
{
  data = d;

    left = l;
    right = r; 
   }
   public void setData(E d) 
{
  data = d;
   }
public E getData()
{
    return data;
}
   public Node<E> getRight() 
{
  return right;
   }
public void  setRight(Node<E> nd)
{
    right = nd;
}
   public Node<E> getLeft()
{
    return left;
}
public void  setLeft(Node<E> nd)
{
    left = nd;
}
public Node<E> getParent()
{
    return parent;
}
public void  setParent(Node<E> nd)
{
    parent = nd;
}
}

Im trying to follow what you said, this is my test class public class BSTTest { public void testInsert() { int height; BST myTree = new BST(); myTree.insert(1); }

}

but when i compile i get the error of unexpected type, it says if found an int but requires a reference on the line of BST myTree = new BST(); what does that mean?

Upvotes: 0

Views: 2695

Answers (1)

vikingsteve
vikingsteve

Reputation: 40388

Yes, make a class called BSTTest and create methods to test each of the public methods in BST.

If you use JUnit, you can use annotations and a standard naming convention

public class BSTTest {
    @Test
    public void testInsert() {
        BST<String> bst = new BST<String>();
        String s = "hello";
        bst.insert(s);
        AssertTrue("I should get back what I put in!", bst.find(s));
    }

    @Test
    public void testDelete() {
        // etc...
    }

}

Then, you can run this 'Unit Test' in your java IDE (such as IntelliJ IDEA) or, if you have it set up, via maven: mvn test.

Also, I think your find() method could return boolean?

good luck!

Upvotes: 1

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