Question

java中如何实现哈希映射?

Answer 1

import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;
class Student
{
	String name;
	int age;
	public Student(String name,int age)
	{
		this.name=name;
		this.age=age;
	}
}
public class HashMapTest
{
	public static void main(String[] args)
	{
		HashMap hm=new HashMap();
		Student s1=new Student("Tom",21);
		Student s2=new Student("Jerry",25);
		Student s3=new Student("Lee",22);
		Student s4=new Student("Lily",29);
		hm.put("Tom",s1);
		hm.put("Jerry",s2);
		hm.put("Lee",s3);
		hm.put("Lily",s4);
		Student s=(Student)hm.get("Tom");
		System.out.println("学生对象的名称为:"+s.name);
		Set keySet=hm.keySet();
		Iterator itr=keySet.iterator();
		while(itr.hasNext())
		{
			String keys=(String)itr.next();
			Student ss=(Student)hm.get(keys);
			System.out.println("迭代输出学生对象的名称为;"+ss.name+"年龄为:"+ss.age);
		}
	}
}