1.使用Map接口的实现类完成员工工资(姓名–工资)的摸拟：
1)添加几条信息
2)列出所有的员工姓名
3列出所有员工姓名及其工资
4)删除名叫“Tom”的员工信息
5)输出Jack的工资，并将其工资加1000元(通过取值实现)
6)将所有工资低于1000元的员工的工资上涨20%(通过取值实现)

public static void main(String[] args) {Map<String, Worker> map = new HashMap<>();Worker worker1 = new Worker("张三", 800);Worker worker2 = new Worker("李四", 2500);Worker worker3 = new Worker("王五", 900);Worker tom = new Worker("Tom", 3000);Worker jack = new Worker("Jack", 2100);map.put("张三", worker1);map.put("李四", worker2);map.put("王五", worker3);map.put("Tom", tom);map.put("Jack", jack);Set<String> names = map.keySet();Iterator<String> iterator = names.iterator();while (iterator.hasNext()) {System.out.println(iterator.next());}iterator = names.iterator();while (iterator.hasNext()) {String name = iterator.next();System.out.println(name + "：" + map.get(name).salary);}map.remove("Tom");System.out.println("Jack的工资为：" + map.get("Jack").salary);map.get("Jack").setSalary(map.get("Jack").getSalary() + 1000);System.out.println("Jack变动后的的工资："+map.get("Jack").salary);Collection<Worker> values = map.values();Iterator<Worker> iterator1 = values.iterator();while (iterator1.hasNext()) {Worker w = iterator1.next();if (w.getSalary() < 1000)w.setSalary(w.getSalary() * 1.2);}System.out.println(map);}static class Worker {String name;double salary;public Worker(String name, int salary) {this.name = name;this.salary = salary;}public String getName() {return name;}public void setName(String name) {this.name = name;}public double getSalary() {return salary;}public void setSalary(double salary) {this.salary = salary;}@Overridepublic String toString() {return "Worker{" +"name='" + name + '\'' +", salary=" + salary +'}';}}

2.分析以下需求，并用代码实现：
(1)定义一个学生类Student，包含属性：姓名(String name)、年龄(int age)
(2)定义Map集合，用Student对象作为key，用字符串(此表示表示学生的住址)作为value
(3)利用三种方式遍历Map集合中的内容

 public static void main(String[] args) {HashMap<Student,String> students=new HashMap<>();students.put(new Student("张三",22),"河北省");students.put(new Student("李四",25),"河南省");students.put(new Student("王五",27),"湖北省");students.put(new Student("赵六",23),"湖南省");// 方法一Set<Student> keySet = students.keySet();for (Student stu:keySet) {System.out.println(stu+" , "+students.get(stu));}//方法二Collection<String> values=students.values();for (String r:values) {System.out.println(r);}//方法三Set<Map.Entry<Student, String>> entrySet = students.entrySet();for (Map.Entry<Student, String> a:entrySet) {System.out.println(a);}}
// 创建一个学生类
public class Student {private String name;private int age;public Student(String name, int age) {this.name = name;this.age = age;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}@Overridepublic String toString() {return "Student{" +"name='" + name + '\'' +", age=" + age +'}';}
}

3.统计一个字符串中字母字符，数字字符出现的次数。(不考虑其他字符)

public static void main(String[] args) {String str="wqewqdadsa321324564dwqd32as1d56qw1da41s65d4qw1d31as32d13q";Map<String,Integer> map=new HashMap<>();// key : zm 代表字母  num 代表数字// values : 代表出现次数for (int i = 0; i <str.length() ; i++) {char c=str.charAt(i);if(Character.isAlphabetic(c)){if(map.containsKey("zm")){map.put("zm",map.get("zm")+1);}else {map.put("zm",1);}}else {if(map.containsKey("num")){map.put("num",map.get("num")+1);}else {map.put("num",1);}}}System.out.println(map);}