package com.dj;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

import java.util.function.*;

class PlainOld{

private static int last_id = 1;

private int id;

public PlainOld() {

id = PlainOld.last_id++;

System.out.println("Creating a PlainOld Object: id = " + id);

}

}

public class Main {

public static void main(String[] args) {

List<String> list = new ArrayList<>(List.of(

"Anna", "Bob", "Chuck", "Dave"));

list.forEach(System.out::println);

calculator(Integer::sum, 10, 25);

calculator(Double::sum, 2.5, 7.5);

Supplier<PlainOld> reference1 = PlainOld::new;

PlainOld newPojo = reference1.get();

System.out.println("Getting Array");

PlainOld[] pojo1 = seedArray(PlainOld::new,10);

calculator((s1, s2) -> s1 + s2, "Hello ","World");

calculator((s1, s2) -> s1.concat(s2), "Hello ","World");

BinaryOperator<String> b1 = (s1, s2) -> s1.concat(s2);

BiFunction<String, String, String> b2 = (s1, s2) -> s1.concat(s2);

UnaryOperator<String> u1 = String::toUpperCase;

System.out.println(b1.apply("Hello ", "World"));

System.out.println(b2.apply("Hello ", "World"));

System.out.println(u1.apply("Hello "));

String result = "Hello".transform(u1);

System.out.println("Result = " + result);

result = result.transform(String::toLowerCase);

System.out.println("Result = " + result);

Function<String, Boolean> f0 = String:: isEmpty;

boolean resultBoolean = result.transform(f0);

System.out.println("Result = " + resultBoolean);

}

private static <T> void calculator(BinaryOperator<T> function, T value1, T value2){

T result = function.apply(value1, value2);

System.out.println("Result of operation:" + result);

}

private static PlainOld[] seedArray(Supplier<PlainOld> reference, int count){

PlainOld[] array = new PlainOld[count];

Arrays.setAll(array, i -> reference.get());

return array;

}

}