舉個例子:
現在有壹個學生類
import java.util.HashMap;
public class Student {
String name;
String sex;
public Student(String n,String s) {
name=n;
sex=s;
}
public String toString(){
return ("姓名:"+name+"\n"+"性別:"+sex+"\n");
}
public static void main(String [] args){
HashMap hm=new HashMap();
Student s1=new Student("張三","男");
Student s2=new Student("李四","男");
Student s3=new Student("小利","女");
//存值是根據學生編號存的學生信息
hm.put("001",s1);
hm.put("002",s2);
hm.put("003",s3);
//查找學生編號是001的學生
//因為hm.get("001")反回的是Object所以加上強轉
Student s=(Student)hm.get("001");
System.out.println(s.toString());
//其余的類似
}
}