unary types and suppliers, knowledge of the rest of the API simply falls into place. In this functional programming tutorial, we will work through a Java Supplier interface example. Java’s functional ...

This is where Java’s functional Consumer interface comes in handy. According to the JavaDoc, the Consumer interface accepts any type of object as input. The java.util.function.Consumer class has one ...

Say you needed to use that fancy string sorter in several places. In Java, we could create a functional interface to share that operation: static class LastNameComparator implements java.util ...

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.