enesoral

List<String> collection =
                Arrays.asList("enes", "emre", "mert", "burak");

collection.stream()
    .filter(s -> s.startsWith("e"))
    .sorted()
    .forEach(System.out::println);

// emre
// enes

enesoral

interface Printable {  
    void printMessage(String message);  
}  

class Message {  
    public Message(String message) {
        System.out.println(message);
    }
}

enesoral

interface Printable {  
    void printMessage();  
}  

class Message {  
  
    public void getMessage(){  
        System.out.println("Hello!");  
    }
}

enesoral

// With anonymous inner class
Thread threadInner = new Thread(new Runnable() {
    @Override
    public void run() {
        System.out.println("Printed inside anon inner class.");
    }
});

// With lambda expression
Thread threadLambda = 

enesoral

greetingFunction = () -> System.out.println("Hello world!");

doubleNumberFunction = a -> a * 2;

addNumberFunction = (a, b) -> {
    return a + b;
};

safeDivideFunction = (a, b) -> {
    if (b == 0) return 0;

enesoral

greetingFunction = public void perform() {
    System.out.println("Hello world!");
};

enesoral

Greeter greeter = new Greeter();
greeter.greet(new Greeting() {
    @Override
    public void perform() {
        System.out.println("Hello world!");
    }
});

enesoral

public class Greeter {
    
    public void greet(Greeting greeting) {
        greeting.perform();
    }

    public static void main(String[] args) {
        Greeter greeter = new Greeter();
        HelloGreeting helloGreeting = new HelloGreeting();
        greeter.greet(helloGreeting);

enesoral

interface Greeting {
    void perform();
}

public class HelloGreeting implements Greeting {
    @Override
    public void perform() {
        System.out.println("Hello world!");
    }
}

enesoral

public class Greeter {
    
    public void greet() {
        System.out.println("Hello world!");
    }
    
    public static void main(String[] args) {
        Greeter greeter = new Greeter();
        greeter.greet();
    }