When you write String::toUpperCase, Java binds each element of the stream (String object) to the toUpperCase() method. This means String::toUpperCase is interpreted as s -> s.toUpperCase() , where ...

8 guidelines for writing reusable Java code. Define the rules for your code; Document your APIs; Follow standard code naming conventions; Write cohesive classes and methods ...

Compared to many other popular programming languages-- such as C and Python -- Java is more verbose. You have to write more Java code to implement the same amount of functionality, and the more code ...