EduCoder Java程序设计---Java 集合框架

超、凢脫俗 2023-09-29 03:19 19阅读 0赞

**第1关 [集合的基本使用][Link 1]**

package step1;
    
    import java.util.ArrayList;						//导包
    
    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 **********/
    	}
    	
    }

**第2关 [ArrayList集合的增删改查][ArrayList]**

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(0);
    		list.remove(list.size()-1);
    		list.add("hello");
    		list.add("educoder");
    		list.set(2,"list");
    		for(Object tmp : list){
    			System.out.println(tmp);
    		}
    		/********** End **********/
    	}
    }

**第3关 [集合的体系结构][Link 2]**

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 **********/
    		Map map = new HashMap();
    		map.put("address","www.educoder.net");
    		return map;
    		/********** End **********/
    	}	
    	
    }

**第4关 [泛型][Link 3]**

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 **********/
    		Scanner scanner = new Scanner(System.in);
    		
    		List<String>list2 = new ArrayList<String>();
    		for(int i = 0 ; i < 3 ; i++ )
    			list2.add(scanner.next());
    		for(int i = 0 ; i < 3 ; i++){
    			System.out.println("集合的第" + (i+1)+"个数据为："+list2.get(i));
    		}
    		
    		
    		
    		
    		/********** End **********/
    	}
    	
    }

**第5关 [Map集合的增删改查][Map]**

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 **********/
    	}
    	
    }

**第6关 [选择题][Link 4]**![36a53969508046ef897da26bc4b63758.png][]

[Link 1]: https://www.educoder.net/tasks/ffbie5krwp29
[ArrayList]: https://www.educoder.net/tasks/mzfh26g8pb5o
[Link 2]: https://www.educoder.net/tasks/8qa6oer7sv2f
[Link 3]: https://www.educoder.net/tasks/qkju9ybvox28
[Map]: https://www.educoder.net/tasks/j8pmfnqofbkc
[Link 4]: https://www.educoder.net/tasks/6pynioklq548
[36a53969508046ef897da26bc4b63758.png]: https://img-blog.csdnimg.cn/36a53969508046ef897da26bc4b63758.png