Casting a real number to Comparable in java?

Question

Let´s say I have a method that inserts a number into a Binary Tree

public BinaryNode insert(Comparable x, BinaryNode t) {
    //Logic here
}

BinaryTree t = new BinaryTree();

How would I cast a number , for example 4 to match the right paremeters on this methods? Ex.

t.insert(4, t ) // I know this wont work, but I wanted to to something like this

Answer 1

It should work fine - it'll be boxed into an integer. Sample code:

public class Test {

    static void foo(Comparable<?> c) {
        System.out.println(c.getClass());
    }

    public static void main(String args[]) throws Exception {
        foo(10);
    }
}

This works even if you use the raw type Comparable, although I'd recommend against that.

Admittedly I strongly suspect that you'd be better off making your BinaryNode (and presumably BinaryTree) class generic, at which point you'd have:

// You shouldn't need to pass in the node - the tree should find it...
BinaryTree<Integer> tree = new BinaryTree<Integer>();
tree.insert(10);