MyClass ht; does not create any object. Instead, it creates a variable (a reference) of type MyClass, and sets its value to null. No object is created. To create an object, you need to explicitly call the class constructor with a new.
MyClass ht = new MyClass();
You can also use ht to refer to an instance of MyClass that has been created (with a new) at some other point in your code.
MyClass myClass = new MyClass(); ...... MyClass ht; ...... ht = myClass; // both ht and myClass are references to the same object...