Lambda Expressions

Test.java

package lambda;

/*
 * Lambda expressions basically express instances of functional interfaces.
 * An interface with single abstract method is called functional interface.
 * An example is java.lang.Runnable.
 * lambda expressions implement the only abstract function and therefore implement functional interfaces
 * */
public class Test {
    public static void main(String[] args) {
        FuntionalInterf interf = (int z) -> System.out.println(">>>>>>> " + (2 * z));

//        interf.setFun(7);
//        interf.getFun();
        WithoutLambda.main();
    }
}

class WithoutLambda {

    public static void main() {
        FuntionalInterf f = new FuntionalInterf() {
            @Override
            public void setFun(int x) {
                System.out.println(":::::: " + (2 * x));
            }
        };
        f.setFun(10);
        f.getFun();
    }
}

// Functional Interface
interface FuntionalInterf {

    // abstract method
    public abstract void setFun(int x);

    //    normal method
    default void getFun() {
        System.out.println("at default method in the Functional Interface");
    }
}