Can have instance mutable fields, parameters, or local variables. Only functional interfaces can use the lambda feature in Java. Abstract classes with only one abstract method cannot use lambdas.

This Java tip introduces additional concepts and techniques related to fields and methods–namely field constants, field-access rules, chaining instance method calls, pass-by-value arguments ...

According to the Java Enhancement Proposal 445: …these changes allow us to write Hello, World! with no access modifiers, no static modifiers, and no String[] parameter, so the introduction of these ...

This post explains how to use variables in Java. ... String also has methods, ... For instance, a constant is a variable whose value never changes.