자바 컬렉션프레임워크(CollectionFramework)_3

안녕하세요 엘체프 GG 임돠.

컬렉션프레임워크 마지막 List,Map 임돠

 

package com.javac.im;
 
import java.util.Iterator;
import java.util.NavigableMap;
import java.util.NavigableSet;
import java.util.TreeMap;
 
public class CollectionFramework3 {
 
    public static void main(String[] args) {
 
//        Map<String, Integer> map = new HashMap<>();
        NavigableMap<String, Integer> map = new TreeMap<>();
    //key의 오름차순(ascending sorting) 정렬(기본지원)
 
        map.put("노르웨이", 14);
        map.put("독일", 14);
        map.put("미국", 11);
        map.put("네덜란드", 9);
        map.put("한국", 6);
 
/*        Set<Map.Entry<String, Integer>> set = map.entrySet();
        //map key = set 공통의 성질(중복 불허)        
        Iterator<Entry<String, Integer>> it = set.iterator();
        //순서가 없다 -> 반복자(iterator) 패턴 -> 열거(나열)        
        while(it.hasNext()){
            Entry<String , Integer> entry = it.next();
            System.out.println(entry.getKey() + " : " + entry.getValue());
        }*/
        
/*        Set<String> set=  map.keySet();        
        Iterator<String> it = set.iterator();        
        while(it.hasNext()){
            String key = it.next();
            System.out.println(key + " : " + map.get(key));            
        }*/
        
/*        NavigableSet<String> set  = map.descendingKeySet();
        //key의 내림차순 정렬
        Iterator<String> it = set.iterator();
        while(it.hasNext()){
            String key =it.next();
            System.out.println(key + " : " + map.get(key));            
        }*/
        
/*        NavigableSet<String> set  = map.navigableKeySet();
        //key의 내림차순 정렬
        Iterator<String> it = set.descendingIterator();        
        while(it.hasNext()){
            String key = it.next();
            System.out.println(key + " : " + map.get(key));            
        }*/
        
        
    }// end main
}// end class
 

 

package com.javac.im;
 
import java.util.NavigableMap;
import java.util.TreeMap;
 
public class CollectionFramework4 {
 
    public static void main(String[] args) {
 
//        Map<String, Integer> map = new HashMap<>();
        NavigableMap<String, Integer> map = new TreeMap<>();
        //key의 오름차순(ascending sorting) 정렬(기본지원)
 
        map.put("노르웨이", 14);
        map.put("독일", 14);
        map.put("미국", 11);
        map.put("네덜란드", 9);
        map.put("한국", 6);
 
        /*//Java 1.8ver : 함수형(람다 표현식)
        map.forEach((k,v)-> System.out.println(k+", "+v + "개"));*/
        
        /*map.entrySet().iterator().forEachRemaining(x->System.out.println(x));*/
        
        /*map.entrySet().forEach(x->System.out.println(x));*/
        
        /*map.keySet().forEach(x->System.out.println(x));//key값만 나열*/
        
        map.keySet().forEach(x->System.out.println(x + " : " + map.get(x)));            
        
    }// end main
}// end class
 

 

package com.javac.im;
 
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
 
public class CollectionFramework5 {
 
    public static void main(String[] args) {
 
        List<String> list = new ArrayList<>();
        
        list.add("박준형");
        list.add("데니안");
        list.add("남근곤");
        list.add("윤계상");
        list.add("손호영");
        list.add("김태우");
        
/*        list.sort(new Comparator<Object>() {
            @Override
            public int compare(Object o1, Object o2) {                
//                return o1.toString().compareTo(o2.toString());//오름차순
                return o2.toString().compareTo(o1.toString());//내림차순
            }
        });
        list.forEach(x->System.out.println(x));*/
        //체이닝프로그램
        list.stream().sorted(Comparator.naturalOrder()).forEach(x->System.out.println(x));
        
        
    }// end main
}// end class
 

 

감사합니다.