IntBinaryOperator is a functional interface in Java 8 from java.util.function package. This interface expects two parameters of type int as input and produces an int type result. IntBinaryOperator can be used as an assignment target for a lambda expression or method reference. It contains only one abstract method: applyAsInt().Syntax@FunctionalInterface public interface IntBinaryOperator {  int applyAsInt(int left, int right) ... Read More

Function interface is a functional interface from java.util.function package. This interface expects one argument as input and produces a result. Function interface can be used as an assignment target for a lambda expression or method reference. It contains one abstract method: apply(), two default methods: andThen() and compose() and one static method: identity().Syntax@FunctionalInterface ... Read More

DoubleSupplier interface is a built-in functional interface defined in java.util.function package. This functional interface doesn’t expect any input but produces a double-valued output. DoubleSupplier interface can be used as an assignment target for lambda expression and method reference. This interface contains only one abstract method: getAsDouble().Syntax@FunctionalInterface public interface DoubleSupplier {    double getAsDouble(); }Example of Lambda Expressionimport ... Read More

The functional interface is a simple interface with only one abstract method. A lambda expression can be used through a functional interface in Java 8. We can declare our own/custom functional interface by defining the Single Abstract Method (SAM) in an interface.Syntaxinterface CustomInterface {    // abtstact method }Example@FunctionalInterface interface CustomFunctionalInterface {    void display(); } public ... Read More

ObjLongConsumer is a functional interface from java.util.function package. This interface accepts an object-valued and long-valued argument as input but doesn't produce any output. ObjLongConsumer can be used as an assignment target for lambda expression and method reference and contains only one abstract method: accept().Syntax@FunctionalInterface public interface ObjLongConsumer {  void accept(T t, long value) }Exampleimport java.util.function.ObjLongConsumer; ... Read More

A functional interface is a special kind of interface with exactly one abstract method in which lambda expression parameters and return types are matched. It provides target types for lambda expressions and method references.Rules for a functional interfaceA functional interface must have exactly one abstract method.A functional interface has any number of ... Read More

LongFunction is an in-built functional interface defined in java.util.function package. This functional interface expects a long-valued parameter as input and produces a result. LongFunction interface can be used as an assignment target for a lambda expression or method reference. It contains only one abstract method: apply().Syntax@FunctionalInterface public interface LongFunction {  R apply(long value) }Exampleimport java.util.function.LongFunction; ... Read More

LongBinaryOperator is a part of the functional interface from java.util.function package. This functional interface expects two parameters of type long as the input and produces a long type result. LongBinaryOperator interface can be used as an assignment target for a lambda expression or method reference. It contains only one abstract method, applyAsLong().Syntax@FunctionalInterface public interface LongBinaryOperator { ... Read More

The "this" and "super" references within a lambda expression are the same as in the enclosing context. Since the lambda expression doesn't define a new scope, "this" keyword within a lambda expression signifies "this" parameter of a method where the lambda expression is residing.In the below example, this.toString() calls the toString() ... Read More

IntConsumer interface is a functional interface from java.util.function package in Java 8. This interface accepts a single int-valued argument as input but doesn't produce any output. Since it is a functional interface, it can be used as an assignment target for a lambda expression or method reference. It contains one abstract method: accept() and ... Read More