import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;    

public class SetsLession {
   public static void main(String[] args) {
   HashMap hashMap = new HashMap<>();
   hashMap.put("fullname", "Tran Van Chung");
   hashMap.put("age", "30");
   hashMap.put("address", "Hai Phong");
   System.out.println(hashMap.get("fullname"));
   HashMap<Object, Object> hashObj = new HashMap<>();
    hashObj.put(1, "Com");
    hashObj.put(2, "Canh");

    System.out.println(hashObj.get(1));

    HashMap<String, Student> studentList = new HashMap<>();
    Student stu = new Student("SV1","Nguyen Nhu Quynh");
    studentList.put(stu.rollno, stu);
    stu = new Student("SV2", "Hoang Minh Nhi");

    studentList.put(stu.rollno, stu);
    System.out.println(studentList.toString());

    Student std2 = studentList.get("SV1");
    System.out.println("STD2: "+std2);
    studentList.forEach((keyInt, valueInt) -> System.out.println("Key = " + keyInt + ", value = " + valueInt));
    for(String list : studentList.keySet()) {
        System.out.println(list);
    }

    //Cách duyệt các phần tử trong HashMap
    Set<String> keys = hashMap.keySet();
    keys.forEach((key)->{
        System.out.println(key + " : " + hashMap.get(key));
    });
    //kiểm tra key có tồn tại hay không
    boolean keycheck = hashMap.containsKey("address");
    if (keycheck) {
        System.out.println("住所：　"+ hashMap.get("address"));
    } else {
        System.out.println("キーが存在しません");
    }


}