This Session I have written, Those who are given the interview and were not able to write the Java 8 program can read this article and practice the program multiple times, which will clear your Java 8 programming interview, Like as: java 8 programming questions or java 8 coding examples or java 8 sample coding questions or Coding Based Java 8 Coding Interview Question or java 8 streams programs for interview or java 8 coding practice problems or java 8 coding interview questions for exrienced or java 8 coding interview questions for freshers.
1). Write a program of functional Interface in java 8. or Example of functional interface in java 8 or Java 8 Functional Interface Example .
interface Addition {
public int divide(int a, int b);
}
public class FunctionalInterface_Example {
public static void main(String[] args) {
Addition add = (a, b) -> (a / b);
System.out.println(add.divide(20, 10));
}}
2). Whrite a program of lambda expression in Java 8 ? or What is lambda expression in Java 8 program Example ? or Write a Lambda Function example in Java 8 or Write a Lambda Function example
@FunctionalInterface
interface Addition {
public int divide(int a, int b);
}
public class Lambda_Example {
public static void main(String[] args) {
Addition add = (a, b) -> (a / b);
System.out.println(add.divide(20, 10));
}}
3). Write a program of Default method in Java 8 ? or Java Default Method Example or What is Default method in Java 8 ?
@FunctionalInterface
interface xyz {
public void show();
public default void show1() {
System.out.println(“It is default method and body of thid mehtod already defined”);
}
}
public class Default implements xyz {
@Override
public void show() {
System.out.println(“this is abstract mehtod of XYZ interface”);
}
public static void main(String[] args) {
Default d1 = new Default();
d1.show();
d1.show1();
}}
4). How to handle Mutliple Inheritance by Default method ? or Mutlipe Inheritance in Java 8 Default method.
interface Poet{
default void write() {
System.out.println(“Poet writing a Poem”);
}
}
interface Writer{
default void write() {
System.out.println(“Writer writing a Poem”);
}
}
public class MultipleIneritance_DefaultMethod implements Poet,Writer {
@Override
public void write() {
// TODO Auto-generated method stub
Poet.super.write(); // it will print Poet method
}
public static void main(String[] args) {
MultipleIneritance_DefaultMethod md= new MultipleIneritance_DefaultMethod();
md.write();
}
}
5). Write a Java 8 Static method Program ? or Write a Static method program in Java 8 ? or Java 8 Static method example ?
@FunctionalInterface
interface X {
public void x();
public static void showX() {
System.out.println(“Hi this is static method”);
}
}
public class StaticMethod_Example implements X {
@Override
public void x() {
System.out.println(“Abstract method of X interface”);
}
public static void main(String[] args) {
X.showX();// call by X interface name directly but can’t override
}
}
6). Write a Predicate interface program in java 8 ? or Write a Java Predicate Interface Example ?
import java.util.function.Predicate;
public class Predicate_exam {
public static void main(String[] args) {
Predicate<Integer> pr = a -> (a > 18);
System.out.println(pr.test(25));
}
}
7). Write a Consumer Functional Interface program in java 8 ? or Java 8 Consumer Interface program ? or Write a Consumer Interface Example ?
import java.util.function.Consumer;
public class Cosumer_Exam {
public static void main(String[] args) {
Consumer<String> print = x -> System.out.println(x);
print.accept(“java”);
}
}
8). Write a Supplier Functional Interface program in java 8 ? or Java 8 Supplier Interface program ? or Write a Supplier Interface Example ?
public class Supplier_Exam {
public static void main(String[] args) {
Supplier<Double> supplier = () -> Math.random(); // to print randon number every time
System.out.println(supplier.get());
}
}
9). Write a Function Functional Interface program in java 8 ? or Java 8 Function Interface program ? or Write a Function Interface Example ?
import java.util.function.Function;
public class Function_Exam {
public static void main(String[] args) {
Function<String, Integer> func = x -> x.length();
Integer apply = func.apply(“Aryan”);
System.out.println(apply);
}
}
10). Write a UnaryOperator Functional Interface program in java 8 ? or Java 8 UnaryOperator Interface program ? or Write a UnaryOperator Interface Example ?
public class UnaryOperator_Exam {
public static void main(String[] args) {
UnaryOperator<Integer> unaryOperation = x -> x + x;
System.out.println(unaryOperation.apply(5));
}
}
11). Write a BinaryOperator Functional Interface program in java 8 ? or Java 8 BinaryOperator Interface program ? or Write a BinaryOperator Interface Example ?
public class BinaryOperator_Exam {
public static void main(String[] args) {
BinaryOperator<String> binaryOperation = (str1, str2) -> str1 + str2;
System.out.println(binaryOperation.apply(“Aryan”, “Singh”));
}
}
12). Whrite a program of Optional Class in Java 8 ? or What is Optional Class in Java 8 program Example ? or Write a Optional Class example in Java 8 or Write a Optional Class example
import java.util.Optional;
public class Optional_Exam {
public static Optional<String> getName(int id) {
String name =null; // value is coming null from DB
return Optional.ofNullable(name);
}
public static void main(String[] args) {
Optional<String> name = getName(1);
if (name.isPresent()) {
System.out.println(name.get()); // here we are getting name from database & may be name will be null value
}
name.ifPresent(System.out::println);
}
}