Question

我错误地循环遍历FreeEvent对象列表，该列表由String和相应的Enum组成。

private List<FreeEvent> freeEvents = new ArrayList<FreeEvent>();

我的JUnit测试给出了以下错误，这是不言自明的：

org.junit.ComparisonFailure：预计：万圣节之夜[1：免费万圣节晚报2：免费万圣节晚会3：免费]但是：万圣节之夜[3：免费]

我理解错误是什么，但我不知道如何修复循环以使其记住它循环的所有值。

public String displayFreeEvents() {

    String name = null;
    EventType type = null;

    for (int i = 0; i < freeEvents.size(); i++) {
        name = freeEvents.get(i).getEventName();
        type = freeEvents.get(i).getEventType();
    }

    String event = name + ": " + type;
    return event;

}

测试用例

     public void testDisplayFreeEvents() {
    EventHistory eventHistory = new EventHistory();

    FreeEvent event1 = new FreeEvent("Halloween Evening1",EventType.FREE);
    FreeEvent event2 = new FreeEvent("Halloween Evening2",EventType.FREE);
    FreeEvent event3 = new FreeEvent("Halloween Evening3",EventType.FREE);

    eventHistory.addFreeEvent(event1);
    eventHistory.addFreeEvent(event2);
    eventHistory.addFreeEvent(event3);

    assertEquals("Halloween Evening1: FREE"+"\n"+"Halloween Evening2: FREE"+"\n"+"Halloween Evening3: FREE"+"\n",eventHistory.displayFreeEvents());

 }

Answer 1

您必须使用StringBuilder类才能通过迭代构建字符串。

所以，你的方法应该是这样的：

public String displayFreeEvents() {

  StringBuilder stringBuilder = new StringBuilder();

  for (int i = 0; i < freeEvents.size(); i++) {
    String name = "", type = "";
    name = freeEvents.get(i).getEventName();
    type = freeEvents.get(i).getEventType();
    stringBuilder.append(name+ " " + type); // you can add also the \n character if you wish
  }


  return stringBuilder.toString();

}

循环后写字符串

1 个答案: