好心累,真的是。。打完了一樣也有錯= = 求大神
package 課程選擇;
import java.util.List;
public class ListTest {
public List coursesToSelect;
public ListTest()
{
this.coursesToSelect=new ArrayList();
}
/*用于往coursesToSelect中添加備選課程*/
? ?
public void testAdd(){
//創(chuàng)建一個課程對象,并通過調(diào)用add方法,添加到備選課程List中
Course cr1=new Course("1","數(shù)據(jù)結(jié)構(gòu)");
coursesToSelect.add(cr1);
Course temp=(Course)coursesToSelect.get(0);
System.out.println("添加了課程"+temp.id+":"+temp.name);
Course cr2=new Course("2","C語言");
coursesToSelect.add(0,cr2);
Course temp2=(Course)coursesToSelect.get(0);
System.out.println("添加了課程"+temp2.id+":"+temp2.name);
/*以下方法會拋出數(shù)組下標(biāo)越界異常
Course cr3=new Course("3","List");
coursesToSelect.add(4,cr3);*/
Course[] course={new Course("3","離散數(shù)學(xué)"),new Course("4","匯編語言")};
coursesToSelect.add(Arrays.asList(course));
Course temp3=(Course)coursesToSelect.get(2);
Course temp4=(Course)coursesToSelect.get(3);
System.out.println("添加了課程"+temp3.id+":"+temp3.name);
System.out.println("添加了課程"+temp4.id+":"+temp4.name);
Course[] course2={new Course("5","高等數(shù)學(xué)"),new Course("6","大學(xué)英語")};
coursesToSelect.addAll(2,Arrays.asList(course2));
Course temp5=(Course)coursesToSelect.get(2);
Course temp6=(Course)coursesToSelect.get(3);
System.out.println("添加了課程"+temp5.id+":"+temp5.name);
System.out.println("添加了課程"+temp6.id+":"+temp6.name);
}
//取得List 中的元素方法
public void testGet(){
int size=coursesToSelect.size();
System.out.println("有如下課程可以選擇:");
for(int i=0;i<size;i++)
{
Course cr=(Course)coursesToSelect.get(i);
System.out.println("課程:"+cr.id+":"+cr.name);
}
}
public static void main(String args[])
{
ListTest It=new ListTest();
It.testAdd();
It.testGet();
}
}
2016-04-20
public class Course {
public String id;
public String name;
public Course(String id, String name) {
this.id = id;
this.name = name;
}
2016-04-20
先導(dǎo)入import java.util.ArrayList;
然后你在?package 課程選擇 包下新建一個Course類
然后就ok啦~~
2016-04-20
太粗心了吧~報錯的地方是在添加3,4的地方,應(yīng)該是addAll而不是add
Course[] courses={new Course("3","離散數(shù)學(xué)"),new Course("4","匯編語言")};
coursesToSelect.addAll(Arrays.asList(courses));