But as per Java 8 specification this difference is removed means interface can contain the method with implementation. Interface can define default and static methods with implementation code.

In Java 9, Interface is getting more enhanced and now more strengthen, Java 9 interface can declare private methods, keeping intact the feature of the default method introduced by Java 8.

Anonymous inner class callback Anytime we pass an interface with a method implementation to another method in Java, we are using the concept of a callback function.

Java Inheritance and Interface Implementation Examples This project provides examples of Java classes that demonstrate the use of inheritance (extends) and interface implementation (implements). It ...

Abstract classes and interfaces in Java serve fundamentally different purposes. Learn the differences between these Java language elements and how to use them in your programs.

Also, discovering the skeletal implementation may require a global analysis. Java 8 enhanced interfaces alleviate these problems by allowing interfaces to contain (default) method implementations, ...

While languages like Ruby provide the pertinent information you need, why can't Java provide a decent, useable, toString() method right out of the box?