public void testMapRemove() { Scanner scanner=new Scanner(System.in); while(true) { ? ?System.out.println("請輸入想要刪除學生的ID"); ? ? String ID=scanner.next(); //報錯行 ? ? Student stu=map.get(ID); if(stu!=null){ map.remove(ID); System.out.println("成功刪除學生"+map.get(ID).name); break; ?} else { System.out.println("該ID不存在！"); continue; } ?} } Exception in thread "main" java.util.NoSuchElementException at java.util.Scanner.throwFor(Unknown Source) at java.util.Scanner.next(Unknown Source) at com.imooc_collection.SetMap.testMapRemove(SetMap.java:50)