package?ⅣCollectionMap;
import?java.util.ArrayList;
import?java.util.List;
import?java.util.Scanner;
public?class?SetTest?{
????public?List<Course>?coursesToSelect;
????public?SetTest(){
????????coursesToSelect?=?new?ArrayList<Course>();
????}
????public?void?testAdd(){
????????Course[]?courses?=?{new?Course("1.","大學(xué)英語"),new?Course("2.","高等數(shù)學(xué)"),new?Course("3.","微機(jī)原理"),new?Course("4.","數(shù)字電子技術(shù)"),new?Course("5.","模擬電子技術(shù)"),new?Course("6.","自動(dòng)控制技術(shù)")};
????}
????public?void?testForEach(){
????????System.out.println("有如下課程待選(通過for?each訪問):");
????????for?(Course?cr:coursesToSelect){
????????????System.out.println("課程:"+?cr.id?+?"."?+?cr.name);
????????}
????}
????public?static?void?main(String[]?args){
????????SetTest?st?=?new?SetTest();
????????st.testAdd();
????????st.testForEach();
????????//創(chuàng)建一個(gè)學(xué)生對(duì)象
????????Student?student?=?new?Student("1","小明");
????????System.out.println("歡迎學(xué)生:"+?student.name?+?"——選課!");
????????//創(chuàng)建一個(gè)Scanner對(duì)象,用來接收從鍵盤輸入的課程ID
????????Scanner?console?=?new?Scanner(System.in);
????????for?(int?i=0;i<3;i++){
????????????System.out.println("請(qǐng)輸入課程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){
????????System.out.println(111111);
??????//打印輸出,學(xué)生所選課程!
?????for?(Course?cr?:?student.courses){
????????????System.out.println(student.name?+?"選擇了課程:"+?cr.id?+?"."+cr.name);
?????}
????}
}
2019-08-22
沒有添加進(jìn)去 你只創(chuàng)建了 數(shù)組 沒把數(shù)組中的 對(duì)象添加到集合中 肯定啥也遍歷不出來
2019-08-12
主要是你的testAdd()方法中只是創(chuàng)建了對(duì)象,并沒有把創(chuàng)建的課程對(duì)象添加到courseToSelect中
2019-08-06
有沒有數(shù)組越界異常,看看報(bào)錯(cuò)原因,