Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.util.function.IntUnaryOperator;

public class Main {
    public static void main(String[] args) {
        final Integer number1 = 20;
        Integer number2 = 10;

        MessagePrinter printer = new MessagePrinter() {
            @Override
            public void print() {
                // number1 has to be final
                System.out.println("number1 = " + number1);
            }
        };

        // watch here, we accessed number2 and it's not final inside a lambda
        incrementEffectivelyFinalVar(x -> x + number2);
        printer.print();
    }

    public static void incrementEffectivelyFinalVar(IntUnaryOperator operator) {
        System.out.println("operator.applyAsInt(1) = " + operator.applyAsInt(1));
    }
}

interface MessagePrinter {
    void print();
}