Map<String, Integer> items = new HashMap<>();

items.put("A", 10);

items.put("B", 20);

items.put("C", 30);

items.put("D", 40);

items.put("E", 50);

items.put("F", 60);

for (Map.Entry<String,Integer> entry : items.entrySet()){

    System.out.println("key:"+entry.getKey()+";value:"+entry.getValue());

}

//output

A---10

B---20

C---30

D---40

E---50

F---60

items.forEach((k,v)->System.out.println("key : " + k + "; value : " + v));

//output

key : A value : 10

key : B value : 20

key : C value : 30

key : D value : 40

key : E value : 50

key : F value : 60

items.forEach((k,v)->{

    System.out.println("Item : " + k + " Count : " + v);

    if("E".equals(k)){

        System.out.println("Hello E");

    }

});

key : A; value : 10

key : B; value : 20

key : C; value : 30

key : D; value : 40

key : E; value : 50

Hello E

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

arrayList.add("A");

arrayList.add("B");

arrayList.add("C");

arrayList.add("D");

arrayList.add("E");

for (String item:arrayList){

    System.out.println(item);

}

arrayList.forEach(item->System.out.println(item));

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

arrayList.forEach(item->{

    if("C".equals(item)){

        System.out.println(item);

    }

});

arrayList.stream()

        .filter(s-> s.contains("B")||s.contains("C"))

        .forEach(System.out::println);

arrayList.stream()

        .filter(s->s.contains("E"))

        .findFirst().ifPresent(s -> System.out.println(s));