Thread: T and <T>

I am learning generics in my Data Structures class and during the reading I fully understand it but when it comes for me to write my own code and imlement it via a project or assignment, it takes me forever because I have to go back through the book and find spots where it applies to what I'm doing.

Anyways, I have a code piece:

public class TelephoneBinaryTree<T extends Integer> implements BinaryTreeADT<T> 
{
	TelephoneTreeNode<T> root;
 
	int size;
 
	public TelephoneBinaryTree()
	{
		size = 0;
	}
 
 
	public TelephoneBinaryTree(int a, int b, int c)
	{
		root = new TelephoneTreeNode<>(a, b, c);
		size = 1;
	}
 
	public  T getRoot() 
	{
		return root; //Type mismatch: cannot convert from TelephoneTreeNode<T> to T
	}

Why does it give me a mismatch? I cannot find anywhere that explains this.

I don't get it, why isn't it a T?

Originally Posted by that_guy

I don't get it, why isn't it a T?

Because it's not, pure and simple. When you create an ArrayList<String>, the object created isn't a String, is it? You seem to be implying that it should be.