java 实验七 对象集合 实验报告(2)

Worker w2=new Worker(\钱二\,21,3800); Worker w3=new Worker(\孙三\,28,4200); list.add(w1); list.add(w2); list.add(w3); }

}

2) 在第二个记录之前插入一个工人信息 答：插入后代码如下：

package zi;

import java.util.ArrayList; import java.util.List; classWorker { privateintage; private String name; privatedoublesalary; public Worker (){}

public Worker (String name, int age, double salary){ this.name = name; this.age = age; this.salary = salary; }

publicint getAge() { returnage; }

publicvoid setAge(int age) { this.age = age; }

public String getName() { returnname; }

publicvoid setName(String name) { this.name = name; }

publicdouble getSalary(){ returnsalary; }

publicvoid setSalary(double salary){ this.salary = salary; }

publicvoid work(){

System.out.println(name + \); }

@Override

public String toString() {

return\ + age + \ + name + \ + salary + \; } }

publicclass Ex7_3_3{

publicstaticvoid main(String args[]){ List list=new ArrayList(); Worker w1=new Worker(\赵一\,30,5600); Worker w2=new Worker(\钱二\,21,3800); Worker w3=new Worker(\孙三\,28,4200); list.add(w1); list.add(1, w2); list.add(w2); list.add(w3);

Worker w2=new Worker(\孙三\,28,4200); list.remove(3);

for (int i = 0; i < list.size(); i++) { System.out.println(list.get(i)); } } }

运行结果如下,不知道为啥会出现乱码。

2) 删除一个记录的信息 答：其代码如下：

package zi;

import java.util.ArrayList; import java.util.List; classWorker { privateintage; private String name; privatedoublesalary;

public Worker (){}

public Worker (String name, int age, double salary){ this.name = name; this.age = age; this.salary = salary; }

publicint getAge() { returnage; }

publicvoid setAge(int age) { this.age = age; }

public String getName() { returnname; }

publicvoid setName(String name) { this.name = name; }

publicdouble getSalary(){ returnsalary; }

publicvoid setSalary(double salary){ this.salary = salary; }

publicvoid work(){

System.out.println(name + \); }

@Override

public String toString() {

return\ + age + \ + name + \ + salary + \; } }

publicclass Ex7_3_3{

publicstaticvoid main(String args[]){ Listlist=new ArrayList(); Worker w1=new Worker(\赵一\,30,5600); Worker w2=new Worker(\钱二\,21,3800); Worker w3=new Worker(\孙三\,28,4200); list.add(w1); list.add(1, w2); list.add(w2); list.add(w3);

Worker w4=new Worker(\孙三\,28,4200); list.remove(3);

for (int i = 0; i

其运行结果如下所示，也是乱码：

3) 利用for 循环遍历，打印List 中现存所有工人的信息 答：其代码如下：

package zi;

import java.util.ArrayList; import java.util.List; classWorker { privateintage; private String name; privatedoublesalary; public Worker (){}

public Worker (String name, int age, double salary){ this.name = name; this.age = age; this.salary = salary; }

publicint getAge() { returnage; }

publicvoid setAge(int age) { this.age = age; }

public String getName() { returnname; }

publicvoid setName(String name) { this.name = name; }

publicdouble getSalary(){ returnsalary;

}

publicvoid setSalary(double salary){ this.salary = salary; }

publicvoid work(){

System.out.println(name + \); }

@Override

public String toString() {

return\ + age + \ + name + \ + salary + \; } }

publicclass Ex7_3_4{

publicstaticvoid main(String args[]){ List list=new ArrayList(); Worker w1=new Worker(\赵一\,30,5600); Worker w2=new Worker(\钱二\,21,3800); Worker w3=new Worker(\孙三\,28,4200); list.add(w1); list.add(1, w2); list.add(w2); list.add(w3);

Worker w4=new Worker(\孙三\,28,4200); list.remove(3);

for (int i = 0; i < list.size(); i++) { System.out.println(list.get(i)); for (Worker w : list) { } }

}

System.out.println(w); }

其运行结果截图如下，不知道为啥会变这样：