packagecom.swift.lianxi;importjava.util.HashMap;importjava.util.Iterator;importjava.util.Map;importjava.util.Set;/*1.请简述Map 的特点

2.请简述HashMap的特点

3.请简述LinkedHashMap的特点

4.使用代码依次完成：

a).将如下键值对信息存入Map集合中:

"黄晓明", "Baby"

"邓超", "孙俪"

"李晨", "范冰冰"

"大黑牛", "范冰冰"

b).将"李晨"对应的值替换成"白百合"

c).获取"大黑牛"对应的值，如果是"范冰冰"就删除以"大黑牛"为键的元素

5.使用代码完成：往一个Map集合中添加若干元素.获取Map中的所有key, 并使用增强for和迭代器遍历输出每个key

6.使用代码完成：往一个Map集合中添加若干元素.获取Map集合中所有的键值对(Entry)对象, 并使用增强for和迭代器遍历输出每个key和value

7.使用代码完成：将学员的信息作为元素存入HashMap中，

提示：1.每位学生(姓名，年龄)都有自己的家庭住址

2.将学生对象和家庭住址存储到map集合中。学生作为键, 家庭住址作为值。

3.学生姓名相同并且年龄相同视为同一名学生*/

public classDemo1 {public static voidmain(String[] args) {

HashMap map = new HashMap();

map.put("黄晓明", "Baby");

map.put("邓超", "孙俪");

String str1=map.put("李晨", "范冰冰");

map.put("大黑牛", "范冰冰");

System.out.println(map);//如果键值相同,直接put就是替换

String str2=map.put("李晨", "白百合");

System.out.println(map);

System.out.println(str1+"..."+str2);

String str3=map.get("大黑牛");if("范冰冰".equals(str3)) {

map.remove("大黑牛");

}

System.out.println(map);

System.out.println("===========================================");//keySet使用增强for遍历

Set keys =map.keySet();for(String key:keys) {

System.out.println(key+"..."+map.get(key));

}//keySet使用iterator遍历

System.out.println("===========================================");

Set set =map.keySet();

Iterator it=set.iterator();while(it.hasNext()) {

String name=it.next();

System.out.println(name+"..."+map.get(name));

}//entrySet使用增强for遍历

System.out.println("===========================================");

Set> entry =map.entrySet();for(Map.Entrykey:entry) {

System.out.println(key.getKey()+"..."+key.getValue());

}//entrySet使用iterator遍历

System.out.println("===========================================");

Set> set1 =map.entrySet();

Iterator> it1=set1.iterator();while(it1.hasNext()) {

Map.Entry entry1=it1.next();

System.out.println(entry1.getKey()+"..."+entry1.getValue());

}

HashMap students = new HashMap();

students.put(new Student("zhangsan",20), "北京");

students.put(new Student("lisi",21), "上海");

students.put(new Student("wangwu",22), "广州");

students.put(new Student("zhaoliu",23), "深圳");

students.put(new Student("zhaoliu",23), "香港");for(Student stu:students.keySet()) {

System.out.println(stu.toString()+"..."+students.get(stu));

}

}

}classStudent{privateString name;private intage;privateString address;publicString getName() {returnname;

}public voidsetName(String name) {this.name =name;

}public intgetAge() {returnage;

}public void setAge(intage) {this.age =age;

}publicString getAddress() {returnaddress;

}public voidsetAddress(String address) {this.address =address;

}public Student(String name, intage, String address) {super();this.name =name;this.age =age;this.address =address;

}public Student(String name, intage) {super();this.name =name;this.age =age;

}publicStudent() {super();//TODO Auto-generated constructor stub

}

@Overridepublic inthashCode() {final int prime = 31;int result = 1;

result= prime * result + ((address == null) ? 0: address.hashCode());

result= prime * result +age;

result= prime * result + ((name == null) ? 0: name.hashCode());returnresult;

}

@Overridepublic booleanequals(Object obj) {if (this ==obj)return true;if (obj == null)return false;if (getClass() !=obj.getClass())return false;

Student other=(Student) obj;if (address == null) {if (other.address != null)return false;

}else if (!address.equals(other.address))return false;if (age !=other.age)return false;if (name == null) {if (other.name != null)return false;

}else if (!name.equals(other.name))return false;return true;

}

@OverridepublicString toString() {return "Student [name=" + name + ", age=" + age + ", address=" + address + "]";

}

}