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public class RamdaTest {
interface Func{
public int calc(int a, int b);
}
public static void main(String[] args) {
new Thread(new Runnable() {
@Override
public void run() {
System.out.println(“Hello Original”);
}
}).start();;
new Thread( ()–> {
System.out.println(“Hello Ramda”);
}).start();;
Func add = (int a, int b) –> {
return a + b;
};
Func sub = (int a ,int b) –> a – b;
System.out.println(“Ramda Add : “ + add.calc(1, 2));
System.out.println(“Ramda Sub : “ + sub.calc(1, 2));
int result = add.calc(1, 3) + sub.calc(2, 4);
System.out.println(“Randa calc : “ + result);
//forEach
System.out.println(“forEach”);
Arrays.asList(1,2,3).stream()
.forEach(System.out::print);
System.out.println();
//map
System.out.println(“map”);
Arrays.asList(1,2,3).stream()
.map(i –> i*i)
.forEach(System.out::print);
//limit ->해당 번째까지만
System.out.println();
System.out.println(“limit”);
Arrays.asList(1,2,3).stream()
.limit(1)
.forEach(System.out::print);
//skip -> 해당 index를 빼고
System.out.println();
System.out.println(“skip”);
Arrays.asList(1,2,3).stream()
.skip(1)
.forEach(System.out::print);
//filter -> 규칙에 해당되는것만
System.out.println();
System.out.println(“filter”);
Arrays.asList(1,2,3).stream()
.filter(i–> 3>i)
.forEach(System.out::print);
//flatMap -> Map을 합쳐줌
System.out.println();
System.out.println(“flatMap”);
Arrays.asList(Arrays.asList(1,2),Arrays.asList(3,4,5),Arrays.asList(6,7,8,9)).stream()
.flatMap(i –> i.stream())
.forEach(System.out::print); // 1,2,3,4,5,6,7,8,9
//reduce -> 단일요소로 반환
System.out.println();
System.out.println(“reduce”);
Arrays.asList(1,2,3).stream()
.reduce((a,b)–> a–b)
.get(); // -4
//앞에서부터 차근차근 계산됨. 1-2 => -1
// -1 – 3 => -4 이렇게 순서대로 계산
//콜렉션 으로
System.out.println();
System.out.println(“Collectors”);
Arrays.asList(1,2,3).stream()
.collect(Collectors.toList());
Arrays.asList(1,2,3).stream()
.iterator();
}
}
|
cs |
