为什么我运行后 1:数据结构 和2:C语言 未添加到学生类Course中 已解决!!!!谢谢
package test3.collection;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
public class SetTest {
public List<Course>coursesToSelect;
public SetTest(){
coursesToSelect=new ArrayList<Course>();
}
public void testAdd(){
//创建一个课程对象,并通过调用add方法,添加到备选课程List中
Course cr1=new Course("1:","数据结构");
coursesToSelect.add(cr1);
Course temp=(Course)coursesToSelect.get(0);
// System.out.println("添加了课程:"+temp.id+temp.name);
Course cr2=new Course("2:","C语言");
coursesToSelect.add(0, cr2);
Course temp2=(Course)coursesToSelect.get(0);
// System.out.println("添加了课程:"+temp2.id+temp2.name);
Course[] course={new Course("3","离散数学"),new Course("4","汇编语言")};
coursesToSelect.addAll(Arrays.asList(course));
Course temp3=(Course)coursesToSelect.get(2);
Course temp4=(Course)coursesToSelect.get(3);
// System.out.println("添加了两门课程:"+temp3.id+':'+temp3.name+';'
// +temp4.id+':'+temp4.name);
Course[] course2={new Course("5","高等数学"),new Course("6","大学英语")};
coursesToSelect.addAll(2,Arrays.asList(course2));
Course temp5=(Course)coursesToSelect.get(2);
Course temp6=(Course)coursesToSelect.get(3);
// System.out.println("添加了两门课程:"+temp5.id+':'+temp5.name+';'
// +temp6.id+':'+temp6.name);
/*Course cr3=new Course("2:","C语言");
coursesToSelect.add(6, cr3);
Course temp7=(Course)coursesToSelect.get(6);
System.out.println("添加了课程:"+temp7.id+temp7.name);
*/
}
/*
* 通过for each方法访问集合元素
*/
public void testForEach(){
System.out.println("有如下课程待选:(for each访问)");
for(Object obj:coursesToSelect){
Course cr=(Course)obj;
System.out.println("课程:"+cr.id+cr.name);
}
}
public static void main(String[] args) {
SetTest st=new SetTest();
st.testAdd();
st.testForEach();
//创建一个学生对象
Student student=new Student("1","小明");
System.out.println("欢迎学生:"+student.name+"选课!");
//创建一个Scanner对象,用来接收从键盘输入的课程ID
Scanner console=new Scanner(System.in);
for(int i=0;i<3;i++){
System.out.println("请输入课程ID");
String courseId=console.next();
for(Course cr:st.coursesToSelect){
if(cr.id.equals(courseId)){
student.courses.add(cr);
}
}
}
st.testForEachForSet(student);
}
public void testForEachForSet(Student student){
//打印输出,学生所选的课程!
for(Course cr:student.courses){
System.out.println("选择了课程:"+cr.id+":"+cr.name);
}
}
}已解决!!!!谢谢