public static void main(String[] args){
Map map = new HashMap(); //定義Map集合對(duì)象
map.put(“apple”,“新鮮的蘋果”); //向集合中添加對(duì)象
map.put(“computer”,“配置優(yōu)良的計(jì)算機(jī)”);
map.put(“book”,“堆積成山的圖書”);
Collection values = map.values(); //獲取Map集合的value集合
for(Object object:values){
System.out.println(“鍵值:”+object.toString()); //輸出鍵值對(duì)象
}
}

Interface Map<K,V>

public class MapDemo {
?? ?public static void main(String[] args) {
?? ??? ?Map<String, String> map = new HashMap<>();

?? ??? ?map.put("001", "小明");
?? ??? ?map.put("002", "小紅");
?? ??? ?System.out.println(map);// {001=小明, 002=小紅}
?? ??? ?
?? ??? ?map.put("002", "小黑");
?? ??? ?System.out.println(map);// {001=小明, 002=小黑}
?? ?}
}

public class MapDemo2 {
	public static void main(String[] args) {
		Map<String, String> map = new HashMap<>();

		map.put("001", "小明");
		map.put("002", "小紅");
		map.put("003", "小黑");
		System.out.println(map);//{001=小明, 002=小紅, 003=小黑}
		
		System.out.println(map.size());//3
		
		//V remove(Object key)根據(jù)鍵刪除鍵值對(duì)元素
		System.out.println(map.remove("001"));//小明
		
		System.out.println(map);//{002=小紅, 003=小黑}
		
		System.out.println(map.containsKey("002"));//true
		System.out.println(map.containsValue("小黑"));//true
		
		map.clear();
		System.out.println(map.isEmpty());//true
		
		System.out.println(map);//{}
		
	}
}

public class MapDemo2 {
	public static void main(String[] args) {
		Map<String, String> map = new HashMap<>();

		map.put("001", "小明");
		map.put("002", "小紅");
		map.put("003", "小黑");
		System.out.println(map);// {001=小明, 002=小紅, 003=小黑}

		System.out.println(map.get("001"));// 小明
		System.out.println(map.get("011"));// null

		// keySet獲取所有鍵
		Set<String> keySet = map.keySet();
		for (String k : keySet) {
			System.out.println(k);
		}
		/*
		 * 001 002 003
		 */

		// 獲取所有值的集合
		Collection<String> values = map.values();
		for (String v : values) {
			System.out.println(v);
		}
		/*
		 * 小明 小紅 小黑
		 * 
		 */
	}
}