package java8;

import java.util.*;

import java.util.function.BinaryOperator;

import java.util.stream.Collectors;

import java.util.stream.IntStream;

import java.util.stream.Stream;

import static java.util.Arrays.asList;

public class StreamsLesson {

public static void main(String[] args) {

List<String> list = new ArrayList<>();

list.add("one");

list.add("two");

for(String s : list) {

System.out.println(s);

}

Iterator<String> iterator = list.iterator();

while (iterator.hasNext()) {

System.out.println(iterator.next());

}

Stream<String> stringStream = list.stream();

stringStream.forEach(x -> System.out.println(x));

for(String s : list) {

if(s.equals("one")) {

System.out.println(s);

}

}

stringStream = list.stream();

stringStream.filter(x -> x.equals("one")).forEach(x -> System.out.println(x));//only once

stringStream = list.stream();

Stream<String> stringStream1 = stringStream.filter((x) -> {

System.out.println("hello");

return x.equals("one");

});//lazy

stringStream1.forEach(x -> System.out.println(x));//eager

Set<String> st = Stream.of("one", "two").collect(Collectors.toSet());//eager

List<String> list1 = Stream.of("one", "two").map(x -> x.toUpperCase()).collect(Collectors.toList());

List<String> list2 = Stream.of("one", "two").filter(x -> x.equals("one")).collect(Collectors.toList());

List<String> list3 = Stream.of(asList("one", "two"), asList("three", "four")).flatMap(x -> x.stream()).collect(Collectors.toList());

int value = Stream.of(1, 2).min(Comparator.comparing(x -> x)).get();

int value2 = Stream.of(1, 2).max(Comparator.comparing(x -> x)).get();

int count = Stream.of(1, 2, 3).reduce(0, (acc, element) -> acc + element);

int accomulator = 0;

for(int element : new int[]{1,2,3}) {

accomulator += element;

}

BinaryOperator<Integer> accumulator = (acc, element) -> acc + element;

int count2 = accumulator.apply(

accumulator.apply(

accumulator.apply(0, 1),

2),

3);

Stream.of("one", "two").sorted().collect(Collectors.toList());

Stream.of("one", "two").limit(1).collect(Collectors.toList());

Stream.of("one", "one").distinct().collect(Collectors.toList());

Stream.of("one", "one").skip(1).collect(Collectors.toList());

Stream.of("one", "two").filter(x -> x.equals("one")).findAny().get();

Stream.of("one", "two").filter(x -> x.equals("one")).findAny().isPresent();

Stream.of(1, 2).mapToInt(x -> x).sum();

Stream.of(1, 2).count();

Stream.of("one", "two").peek(x -> x.toUpperCase()).findFirst().get();

IntStream intStream = Stream.of(1, 2).mapToInt(x -> x);

intStream.summaryStatistics().getAverage();

}

}