Question

我对React很新，并且在尝试添加＆＃34; if＆＃34;时遇到了一些麻烦。传播组件中的陈述：

示例代码：

class CalenderView extends Component {
  parseActivitiesForCalendar = (activities) => {
    return activities.map((activity) => {
      return {
        ...activity,
        id: activity.id,
        title: Dates.getTimeString(activity.startDate) +" - "+ activity.desc,
        start: Dates.getDateTimeFromUnix(activity.startDate),
        end: Dates.getDateTimeFromUnix(activity.endDate)
      }
    })
  }

使用＆＃34;标题＆＃34;，我正在尝试添加以下条件：

if(Dates.getTimeString(activity.startDate)=="00:00") {
    title: "All Day - "+ activity.desc,
} else {
  title: Dates.getTimeString(activity.startDate) +" - "+ activity.desc,
}

但不确定如何写这个。有什么想法吗？

Answer 1

使用ternary operator：

这样写

return {
    ...activity,
    id: activity.id,

    title: Dates.getTimeString(activity.startDate) == "00:00" ? "All Day - " + activity.desc : Dates.getTimeString(activity.startDate) +" - "+ activity.desc,

    start: Dates.getDateTimeFromUnix(activity.startDate),
    end: Dates.getDateTimeFromUnix(activity.endDate)
}

Answer 2

如果在对象中不起作用，您可以使用三元运算符来获得所需的结果。

class CalenderView extends Component {
  parseActivitiesForCalendar = (activities) => {
    return activities.map((activity) => {
      return {
        ...activity,
        id: activity.id,
        title: (Dates.getTimeString(activity.startDate)=="00:00")? "All Day - "+ activity.desc : Dates.getTimeString(activity.startDate) +" - "+ activity.desc,
        start: Dates.getDateTimeFromUnix(activity.startDate),
        end: Dates.getDateTimeFromUnix(activity.endDate)
      }
    })
  }

Answer 3

这应该有所帮助。

title: Dates.getTimeString(activity.startDate)=="00:00"? "All Day - "+ activity.desc : Dates.getTimeString(activity.startDate) +" - "+ activity.desc;

如果是扩展运算符中的else语句

3 个答案: