I am working on an assignment but I got stuck in a step, I basically have 2 classes and 1 interface, class1 contains 2 constructors and 2 methods, class2 implements the interface everything is working fine however I was told to create a reference to class1 in class2, I have been searching around but I am having trouble finding information, can someone point me to the right direction of a document where I can find information on what a reference to a class is and how to add it, I have found reference to objects but not to classes