package entity;
public class Student {
private String name;//学员姓名
private String sex;//学员性别
public Student(){
}
public Student(String name,String sex){
this.name = name;
this.sex = sex;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
}
package test;
import java.util.HashMap;
import java.util.Map;
import entity.Student;
public class HashMapDemo {
public static void main(String[] args) {
//1.创建学员对象
Student student1 = new Student("哪吒","男");
Student student2 = new Student("木吒","男");
Student student3 = new Student("莉莉","女");
//2.创建保存“键-值对" 的集合对象
Map students = new HashMap();
//3.把英文名称与学员对象按照“键- 值对”的方式存储在HashMap中
students.put("Naza",student1);
students.put("Muza",student2);
students.put("Lili",student3);
//4.打印键集
System.out.println("键集:"+students.keySet());
//5.打印值集
System.out.println("值集:"+students.values());
//6.打印键-值对集合
System.out.println("键-值对集合:"+students);
String key = "Jack";
//7.判断是否存在“Jack”这个键
if(students.containsKey(key)){
Student student = (Student)students.get(key);
System.out.println(key+"对应的学员姓名是:"+student.getName()+";性别是:"+student.getSex());
}
}
}