A Java class inherits these methods and can override any method that’s not declared final. For example, the non- final toString() method can be overridden, whereas the final wait() methods cannot.

Polymorphism in method overriding. It’s possible to change the return type of an overridden method if it is a covariant type. A covariant type is essentially a subclass of the return type. Here ...

Java Supplier interface tutorial. As you can see, the code for the class that implements Java’s Supplier interface is fairly simple. The only requirements are the class declaration and the ...