JavascriptIF/ELSE-縮短功能

我正在使用 JavaScript IF/ELSE 以更好地理解它的作業原理。作為練習，我選擇了一家商店的以下作業時間：

• 早上 6 點到下午 6 點 = 營業
• 下午 6 點至早上 6 點 = 關閉

然后我創建了一個函式，它根據“時間”和“期間”這兩個值回傳“打開”或“關閉”這個詞。

function shopHours(time,period) {
if (time === 6 && period === 'AM') {
return 'Open';
} else if (time === 6 && period === 'AM') {
return 'Open';
} else if (time === 7 && period === 'AM') {
return 'Open';
} else if (time === 8 && period === 'AM') {
return 'Open';
} else if (time === 9 && period === 'AM') {
return 'Open';
} else if (time === 10 && period === 'AM') {
return 'Open';
} else if (time === 11 && period === 'AM') {
return 'Open';
} else if (time === 12 && period === 'PM') {
return 'Open';
} else if (time === 1 && period === 'PM') {
return 'Open';
} else if (time === 2 && period === 'PM') {
return 'Open';
} else if (time === 3 && period === 'PM') {
return 'Open';
} else if (time === 4 && period === 'PM') {
return 'Open';
} else if (time === 5 && period === 'PM') {
return 'Open';
} else {
return 'Closed';} 
}

一切正常。但是，我希望能夠縮短代碼，因為它看起來太混亂了。

然后我嘗試了以下方法：

function shopHours(time,period) {
if(time <= 6 && period === 'AM') {
return 'Closed';
} else if (time >= 6 && period === 'PM') {
return 'Closed';
} else if (time === 12 && period === 'PM') {
return 'Open';
} else {
return 'Open';}
}

第二個代碼也可以正常作業并且要短得多，但是有一個我不知道如何解決的問題。當時間和時段設定為 12 點和下午時，結果應該是“關閉”，但我不確定如何實作。

我嘗試添加以下代碼，但似乎無法解決此問題。

 else if (time === 12 && period === 'AM') {
return 'Closed';
}

我將非常感謝任何愿意花一點時間來研究這個問題的人。

謝謝！

uj5u.com熱心網友回復：

您可以將其分解為兩個初始場景，上午或下午。然后檢查小時，看看它應該打開還是關閉。

if (period == "AM") {
    if (time < 6 || time == 12) 
        return "Closed";
    return "Open";
}
else {
    if (time >= 6 && time != 12)
        return "Closed";
    return "Open";
}

uj5u.com熱心網友回復：

在我看來，使用 24 小時格式更容易。然而，必須考慮12PM = 12:00并12AM = 00:00考慮到這一點。

轉換后的比較相當容易。

function shopHours(time, period) {
    let hour = time;
    if (period === 'PM' && hour < 12) hour = hour   12;
    if (period === 'AM' && hour === 12) hour = hour - 12;

    if (hour >= 6 && hour < 18) {
        return 'Open';
    }

    return 'Closed';
}

console.log('12 AM is '   shopHours(12, 'AM')   '. Expected it to be: Closed');
console.log('3 AM is '   shopHours(3, 'AM')   '. Expected it to be: Closed');
console.log('6 AM is '   shopHours(6, 'AM')   '. Expected it to be: Open');
console.log('9 AM is '   shopHours(9, 'AM')   '. Expected it to be: Open');
console.log('12 PM is '   shopHours(12, 'PM')   '. Expected it to be: Open');
console.log('3 PM is '   shopHours(3, 'PM')   '. Expected it to be: Open');
console.log('6 PM is '   shopHours(6, 'PM')   '. Expected it to be: Closed');
console.log('9 PM is '   shopHours(9, 'PM')   '. Expected it to be: Closed');

uj5u.com熱心網友回復：

我的 version.if 目標只是縮短代碼，然后am() and pm()可以省略這些函式，并且可以在呼叫它們的地方添加里面的代碼。那將是 3 行代碼。

function shopHours(time, period){
var result;
function am () {
  Number(time) < 12 && Number(time) >= 6 ? result = "open" : result = "closed";
}
function pm() {
    Number(time) <= 5 || Number(time) === 12 ? result = "open" : result = "closed";
}
period === 'AM' ? am() : pm();

return result;
}

console.log("12 AM is: ", shopHours(12, 'AM'), '; expected: closed');
console.log("3 AM is: ", shopHours(3, 'AM'), '; expected: closed');
console.log("6 AM is: ", shopHours(6, 'AM'), '; expected: open');
console.log("9 AM is: ", shopHours(9, 'AM'), '; expected: open');
console.log("12 PM is: ", shopHours(12, 'PM'), '; expected: open');
console.log("3 PM is: ", shopHours(3, 'PM'), '; expected: open');
console.log("6 PM is: ", shopHours(6, 'PM'), '; expected: closed');
console.log("9 PM is: ", shopHours(9, 'PM'), '; expected: closed');

uj5u.com熱心網友回復：

這可以使用 date 輕松處理。而不是使用 if else，您可以定義openHoursand closeHours。并傳遞當前時間。你可以很容易地進行比較。

樣本：

function shopHours(time, period) {
  let openHour = new Date();
  let closeHour = new Date();
  openHour.setHours(6);
  closeHour.setHours(12   6);

  let curreTime = new Date();
  curreTime.setHours(period === "PM" ? 12   time : time);
  if (curreTime > openHour && curreTime < closeHour) return "Open";
  return "Close";
}

console.log(shopHours(11, "PM"));
console.log(shopHours(12, "AM"));
console.log(shopHours(11, "AM"));
console.log(shopHours(7, "AM"));
console.log(shopHours(5, "AM"));

您也可以只傳遞 currentTime 并進行驗證。

function shopHours(curreTime) {
  let openHour = new Date();
  let closeHour = new Date();
  openHour.setHours(6);
  closeHour.setHours(12   6);
  if (curreTime > openHour && curreTime < closeHour) return "Open";
  return "Close";
}

console.log(shopHours(new Date()));

uj5u.com熱心網友回復：

我的建議：

function shopHours(time, period) {
  var status = "Open";
  if ((period == "AM" && (time < 6 || time == 12)) || (time >= 6 && time != 12)) status = "Closed";
  return status;
}

console.log(shopHours(5, "AM"));
console.log(shopHours(5, "PM"));

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