Java 8 example - forEach

Normal for-loop to loop a List.


List items = new ArrayList<>();
items.add("A");
items.add("B");
items.add("C");
items.add("D");
items.add("E");

for(String item : items){
System.out.println(item);
}

In Java 8, you can loop a List with forEach + lambda expression or method reference


List items = new ArrayList<>();
items.add("A");
items.add("B");
items.add("C");
items.add("D");
items.add("E");

//lambda
//Output : A,B,C,D,E
items.forEach(item->System.out.println(item));

//Output : C
items.forEach(item->{
if("C".equals(item)){
System.out.println(item);
}
});

//method reference
//Output : A,B,C,D,E
items.forEach(System.out::println);

//Stream and filter
//Output : B
items.stream()
.filter(s->s.contains("B"))
.forEach(System.out::println);