import java.util.HashMap;

​

public class Main {

    public static void main(String[] args) {

​

        HashMap<Integer, String> sites = new HashMap<>();

        sites.put(1, "Google");

        sites.put(2, "Jiyik");

        sites.put(3, "Taobao");

        System.out.println("HashMap: " + sites);

​

        // 删除key为2的映射关系

        String siteName = sites.remove(2);  // return Jiyik

        System.out.println("返回值: " + siteName);

        System.out.println("删除后的 HashMap: " + sites);

    }

}