37 lines
866 B
Java
37 lines
866 B
Java
|
// streams/CollectionToStream.java
|
||
|
|
import java.util.*;
|
||
|
|
import java.util.stream.*;
|
||
|
|
|
||
|
|
public class CollectionToStream {
|
||
|
|
public static void main(String[] args) {
|
||
|
|
List<Bubble> bubbles = Arrays.asList(
|
||
|
|
new Bubble(1), new Bubble(2), new Bubble(3));
|
||
|
|
System.out.println(
|
||
|
|
bubbles.stream()
|
||
|
|
.mapToInt(b -> b.i)
|
||
|
|
.sum());
|
||
|
|
|
||
|
|
Set<String> w = new HashSet<>(Arrays.asList(
|
||
|
|
"It's a wonderful day for pie!".split(" ")));
|
||
|
|
w.stream()
|
||
|
|
.map(x -> x + " ")
|
||
|
|
.forEach(System.out::print);
|
||
|
|
System.out.println();
|
||
|
|
|
||
|
|
Map<String, Double> m = new HashMap<>();
|
||
|
|
m.put("pi", 3.14159);
|
||
|
|
m.put("e", 2.718);
|
||
|
|
m.put("phi", 1.618);
|
||
|
|
m.entrySet().stream()
|
||
|
|
.map(e -> e.getKey() + ": " + e.getValue())
|
||
|
|
.forEach(System.out::println);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
/* Output:
|
||
|
|
6
|
||
|
|
a pie! It's for wonderful day
|
||
|
|
phi: 1.618
|
||
|
|
e: 2.718
|
||
|
|
pi: 3.14159
|
||
|
|
*/
|