Educoder题目：Java高级特性 - 集合框架答案解析

    package step1;
    // 导包
    /********** Begin **********/
    import java.util.ArrayList;
    /********** End **********/
    						
    public class HelloWorld {
    
    	@SuppressWarnings("unchecked") 
    	public ArrayList getList() {
    		/********** Begin **********/
    		ArrayList list = new ArrayList();
        list.add("https:www.educoder.net");
    		list.add(2018.423);
    		
    		return list;
    		
    		/********** End **********/
    	}
    	
    }
    
    
    
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
    
    代码解读

    package step2;
    
    import java.util.ArrayList;
    import java.util.Scanner;
    
    public class HelloWorld {
    	
    @SuppressWarnings("unchecked")
    	public static void main(String[] args) {
    		//获取输入的数据并添加至集合
    		Scanner sc = new Scanner(System.in);
    		ArrayList list = new ArrayList<>();
        int length = sc.nextInt();
    		for(int i =0 ; i< length; i++){
    			list.add(sc.next());
    		}
    		/********** Begin *********/	
    		list.remove(length-1);
    		list.remove(0);
    		list.add("hello");
    		list.add("educoder");
    		list.set(2,"list");
    		for(int i=0;i<length;i++){
    			System.out.println(list.get(i));
    		}
    		
    		
    		/********** End **********/
    	}
    }
    
    
    
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
    
    代码解读

    package step3;
    
    import java.util.ArrayList;
    import java.util.HashSet;
    import java.util.Set;
    import java.util.HashMap;
    import java.util.LinkedList;
    import java.util.Map;
    
    public class HelloWorld {
    	
    	public HashSet getHashSet(){
    		/********** Begin **********/
    	    HashSet set = new HashSet();  
        set.add("www.educoder.net");
    		return set;
    		
    		/********** End **********/
    	}
    	
    	public ArrayList getArrayList(){
    		/********** Begin **********/
    		
    		ArrayList list = new ArrayList();
        list.add("www.educoder.net");
        return list;
    		/********** End **********/
    	}
    	
    	public LinkedList getLinkedList(){
    		/********** Begin **********/
    		LinkedList list = new LinkedList();  
        list.add("www.educoder.net");  
    		return list;
    		
    		
    		
    		/********** End **********/
    	}
    	
    	public Map getHashMap(){
    		/********** Begin **********/
    		HashMap map = new HashMap();  
        map.put("address","www.educoder.net");  
    		
    		return map;
    		
    		
    		/********** End **********/
    	}	
    	
    }
    
    
    
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
    
    代码解读

    package step4;
    
    import java.util.*;
    
    public class HelloWorld {
    	
    	
    	public static void main(String[] args) {
    		Scanner sc = new Scanner(System.in);
    		//程序会输入三次数据
    		/********** Begin **********/
        List<String> list = new ArrayList<String>();
    	    for(int i = 0; i<3 ; i++){
    			list.add(sc.next());
    		}
    		for(int i = 0; i<3 ; i++){
    			System.out.printf("集合的第%d个数据为：",i+1);
    			System.out.println(list.get(i));
    		}
    		/********** End **********/
    	}
    	
    }
    
    
    
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
    
    代码解读

    package step5;
    
    import java.util.HashMap;
    import java.util.Map;
    import java.util.Scanner;
    
    public class HelloWorld {
    
    	public static void main(String[] args) {
    		Map<String, Integer> menuDict = new HashMap<>();
    		Scanner sc = new Scanner(System.in);
    		for (int i = 0; i < 5; i++) {
    			menuDict.put(sc.next(),sc.nextInt());
    		}
    		/********** Begin **********/
        menuDict.put("lamb",50);
    		System.out.println(menuDict.get("fish"));
        menuDict.put("fish",100);
        menuDict.remove("noodles");
        System.out.println(menuDict.toString());
    		
    		
    		
    		
    		
    		
    		/********** End **********/
    	}
    	
    }
    
    
    
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
    
    代码解读