reactjs - 错误: Expected an assignment or function call and instead saw an expression no-unused-expressions. How to solve it?

Question

我实际上正在尝试将我的数据库连接到React应用，并且它会在三个不同的地方(向我显示以下“>>”突出显示此错误)

 handleDBReponse(response) {
    const appointments = response;
    const today = moment().startOf("day"); //start of today 12 am
    const initialSchedule = {};
    initialSchedule[today.format("YYYY-DD-MM")] = true;
    const schedule = !appointments.length
      ? initialSchedule
      : appointments.reduce((currentSchedule, appointment) => {
          const { slot_date, slot_time } = appointment;
          const dateString = moment(slot_date, "YYYY-DD-MM").format(
            "YYYY-DD-MM"
          );
>>          !currentSchedule[slot_date]
            ? (currentSchedule[dateString] = Array(8).fill(false))
            : null;
>>          Array.isArray(currentSchedule[dateString])
            ? (currentSchedule[dateString][slot_time] = true)
            : null;
          return currentSchedule;
        }, initialSchedule);
    for (let day in schedule) {
      let slots = schedule[day];
>>      slots.length
        ? slots.every(slot => slot === true) ? (schedule[day] = true) : null
        : null;
    }
    this.setState({
      schedule: schedule
    });
  }

Answer 1

在这三种情况下，您都在做类似

condition ? something = somethingElse : null

因此，如果condition虚假，它将求值为 false null，这实际上没有任何意义。我认为，如果您执行以下操作，则更容易阅读和摆脱警告

if (condition) something = somethingElse

所以在第一种情况下

!currentSchedule[slot_date]
  ? (currentSchedule[dateString] = Array(8).fill(false))
  : null;

应该

if (!currentSchedule[slot_date]) {
  (currentSchedule[dateString] = Array(8).fill(false));
}