Javascript从数组中获取第一个值，然后跳过它

如果我理解正确。。。您想要使用以下数组：

var JANDays = [{day:16, timeStart:"23:00:00"},
               {day:17, timeEnd:"11:00:00"},
               {day:22, timeStart:"23:00:00"},
               {day:23, timeEnd:"07:00:00"}];

而不是你现在拥有的。

在这种情况下，您可以增加索引i以获得数组中的下一个项目，例如：

var JANDays = [{day:16, timeStart:"23:00:00"},
               {day:17, timeEnd:"11:00:00"},
               {day:22, timeStart:"23:00:00"},
               {day:23, timeEnd:"07:00:00"}];
for (var i = 0; i < JANDays.length; i++)
{
    if (thisDayDate == JANDays[i].day) {
        // Notice "JANDays[i+1].timeEnd", this will get the timeEnd of the next item in the array
        // (Beware: i+1 could result in undefined)
        if (isSiteDown(JANDays[i].timeStart, JANDays[i+1].timeEnd)) { 
            showThePage(); 
        } else { 
            console.log('nope');
        }
    }
}

编辑

我仍然不完全理解你在寻找什么，但也许可以看看这个：

var JANDays = [{day:16, timeStart:"23:00:00"},
            {day:17, timeEnd:"11:00:00"},
            {day:22, timeStart:"23:00:00"},
            {day:23, timeEnd:"07:00:00"}];
for (var i = 0; i < JANDays.length; i++)
{
    var day = JANDays[i].day;
    var timeStart = JANDays[i] && JANDays[i].timeStart || "00:00:00";
    var timeEnd = JANDays[i] && JANDays[i].timeEnd;
    var nextTimeEnd = JANDays[i+1] && JANDays[i+1].timeEnd || "23:59:59";
    if (timeEnd) { // This indicates the second day
        console.log(day, timeStart, timeEnd);
    } else {
        console.log(day, timeStart, nextTimeEnd);
    }
}

以上内容将输出到控制台，类似于：

16 "23:00:00" "11:00:00"
17 "00:00:00" "11:00:00"
22 "23:00:00" "07:00:00"
23 "00:00:00" "07:00:00"

每条线路包括：

1. day，然后是
2. timeStart，然后是
3. timeEnd

因此，如果一天是16，那么timeStart和timeEnd将分别是"23:00:00"和"11:00:00"。

但如果当天是17，则timeStart和timeEnd将分别是"00:00:00"和"11:00:00"。

Etc等

这里的想法是，我在循环期间检查timeEnd是否为defined。

也许这对你有帮助？

编辑

如果输出应该是这样的：

16 "23:00:00" "23:59:59"
17 "00:00:00" "11:00:00"
22 "23:00:00" "23:59:59"
23 "00:00:00" "07:00:00"

然后你可以去：

for (var i = 0; i < JANDays.length; i++)
{
    var day = JANDays[i].day;
    // The code below will check to see if timeStart and timeEnd are defined
    // If they are defined then they will be used,
    // otherwise use the specified value after the pipes (||)
    var timeStart = (JANDays[i] && JANDays[i].timeStart) || "00:00:00";
    var timeEnd = (JANDays[i] && JANDays[i].timeEnd) || "23:59:59";
    if (thisDayDate == day) {
        console.log(day, timeStart, timeEnd);
    }
}

您可以使用map，然后检查索引，看看它是奇数还是偶数。类似这样的东西：

var JANDays = [{
    day: 16,
    timeStart: "23:00:00",
    timeEnd: "24:59:59"
  }, //It's Jan 16th Friday 11pm to
  {
    day: 17,
    timeStart: "00:00:00",
    timeEnd: "11:00:00"
  }, //It's Jan 17th                Sat 11am
  {
    day: 22,
    timeStart: "23:00:00",
    timeEnd: "24:59:59"
  }, //It's Jan 22nd Friday 11pm to  
  {
    day: 23,
    timeStart: "00:00:00",
    timeEnd: "07:00:00"
  }
]; //It's Jan 23ed
var alt = JANDays.map(function(item,idx) {
    if (idx % 2) {
        return { day: item.day, timeStart: item.timeStart };
    }
    else {
        return { day: item.day, timeEnd: item.timeEnd };
    }
});
document.getElementById("output").innerHTML = JSON.stringify(alt);

<div id="output"></div>

试试这个：

var JANDays = [{day:16, timeStart:"23:00:00", timeEnd:"24:59:59"},  //It's Jan 16th Friday 11pm to
               {day:17, timeStart:"00:00:00", timeEnd:"11:00:00"},  //It's Jan 17th                Sat 11am
               {day:22, timeStart:"23:00:00", timeEnd:"24:59:59"},  //It's Jan 22nd Friday 11pm to  
               {day:23, timeStart:"00:00:00", timeEnd:"07:00:00"}]; //It's Jan 23ed                Sat  7am
var output = JANDays.map(function(item, index){
  var temp = {};
  temp.day = item.day;
  
  if(index%2 == 0){
    temp.timeStart = item.timeStart;
  }
  else{
    temp.timeEnd = item.timeEnd;
  }
  return temp;
})
console.log(output);