java集合——题4,6
4、(List)写一个函数reverseList,该函数能够接受一个List,然后把该List 倒序排列。 例如:
List list = new ArrayList();
list.add(“Hello”);
list.add(“World”);
list.add(“Learn”); //此时list 为Hello World Learn
reverseList(list); //调用reverseList 方法之后,list 为Learn World Hello
import java.util.ArrayList; import java.util.Iterator; import java.util.List; import com.JiHe.test.Person; public class DaoXu { public static void main(String[] args) { // TODO 自动生成的方法存根 List<String> list =new ArrayList<>(); List<String> reverselist=new ArrayList<>(3); list.add("Hello\t"); list.add("World\t"); list.add("Learn\t"); System.out.print("list= "); for(String str:list){ System.out.print(str); } System.out.println(); for(int i=list.size()-1;i>=0;i--){ reverselist.add(list.get(i)); } System.out.print("reverselist= "); for(String str:reverselist){ System.out.print(str); } } }
6、(List)已知有一个Worker 类如下:
public class Worker
{ private int age;
private String name;
private double salary;
public Worker (){}
public Worker (String name, int age, double salary)
{ this.name = name;
this.age = age;
this.salary = salary; }
public int getAge() { return age; }
public void setAge(int age) { this.age = age; }
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; }
public void work(){
System.out.println(name + “ work”); } }
完成下面的要求
1) 创建一个List,在List 中增加三个工人,基本信息如下:
姓名 年龄 工资
zhang3 18 3000
li4 25 3500
wang5 22 3200
2) 在li4 之前插入一个工人,信息为:姓名:zhao6,年龄:24,工资3300
3) 删除wang5 的信息
4) 利用for 循环遍历,打印List 中所有工人的信息
5) 利用迭代遍历,对List 中所有的工人调用work 方法。
import java.util.ArrayList; import java.util.Iterator; import java.util.List; public class Work { private int age; private String name; private double salary; public Work(){ } public Work(String name,int age,double salary){ this.name=name; this.age=age; this.salary=salary; } public void work(){ System.out.println(name+" work"); } public int getAge() { return age; } public void setAge(int age) { this.age = age; } 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; } @Override public String toString() { return "Work [Age=" + getAge() + ", Name=" + getName() + ", Salary=" + getSalary() + "]"; } public static void main(String[] args){ List<Work> list = new ArrayList<>(); list.add(new Work("zhang3",18,3000)); list.add(new Work("li4",25,3500)); list.add(new Work("wang5",22,3200)); list.add(1,new Work("zhao6",24,3300)); list.remove(3); for(Work w:list){ System.out.println(w); } Iterator<Work> it =list.iterator(); while(it.hasNext()){ it.next().work(); } } }