Java 類和List集合 迭代器遍歷練習題

1.  創建班級類(Classes)，具有兩個屬性：班級人數，班級名稱；創建學生類(Student),具有三個屬性：學生姓名，學號，所在班級(Classes類型對象)，所有屬性都通過構造方法賦值，並具有相應存取器方法。在測試類中，創建存儲Student類型的List，並向其添加十個學生的信息，通過迭代器，迭代該List，並將學生所在班級名稱打印到控制台。

 import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.ListIterator; //定義一個班級類
class Classes{ private int count; private String name; //構造方法
public Classes(int count, String name) { super(); this.count = count; this.name = name; } //getter/setter方法
public int getCount() { return count; } public void setCount(int count) { this.count = count; } public String getName() { return name; } public void setName(String name) { this.name = name; } } //定義一個學生類
class Student { private String name; private String id; private Classes classes; public Student(String name, String id, Classes classes) { this.name = name; this.id = id; this.classes = classes; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getId() { return id; } public void setId(String id) { this.id = id; } public Classes getClasses() { return classes; } public void setClasses(Classes classes) { this.classes = classes; } } public class Test1_06 { public static void main(String[] args) {
 List list = new ArrayList (); Classes cla = new Classes(10, "java0421");  //生成班級

    for (int i = 0; i < 10; i++) {   //循環10遍
        Student s = new Student(""+i, i+"", cla);  //生成學生
        list.add(s);  //添加學生 
 } //通過迭代器，迭代該list集合
    for(ListIterator it = list.listIterator();it.hasNext();) { Object obj = it.next(); if (obj instanceof Student) { Student s = (Student) obj; System.out.println(s.getClasses().getName()); } } } }