Introduction: In Java programming, functional interfaces play a crucial role, especially with the introduction of lambda expressions in Java 8. They provide a way to implement functional programming concepts within the object-oriented paradigm of Java. In this blog post, we'll delve into what functional interfaces are, how they work, and address common questions that Java developers might have about them. What are Functional Interfaces? Functional interfaces are interfaces that contain only one abstract method. They act as a blueprint for lambda expressions, enabling you to treat functionality as a method argument or create concise code. In Java 8, the @FunctionalInterface annotation was introduced to explicitly mark interfaces as functional interfaces, although it's optional. How Do Functional Interfaces Work? Functional interfaces facilitate the implementation of lambda expressions, which are essentially anonymous functions. Lambda expressions provide a way to express inst...
To find the second-highest salary from a list of employees using Java 8 streams, you can follow these steps: Create a list of employees with their salaries. Use Java 8 streams to sort the employees by salary in descending order. Skip the first element (which is the employee with the highest salary). Get the first element of the remaining stream (which is the employee with the second-highest salary). Example code: java import java.util.ArrayList; import java.util.List; class Employee { private String name; private double salary; public Employee (String name, double salary) { this .name = name; this .salary = salary; } public double getSalary () { return salary; } } public class SecondHighestSalary { public static void main (String[] args) { List<Employee> employees = new ArrayList <>(); employees.add( new Employee ( "John" , 60000.0 )); employees.add( new Employe...