我如何检查“HH：mm：ss”中的时间是上午还是下午？ [复制]

Question

我有一系列时间安排。

let data = ["09:00:00", "09:10:00", "09:20:00", "09:30:00", "09:40:00", "09:50:00", "10:00:00", "10:10:00", "10:20:00", "10:30:00", "10:40:00", "10:50:00", "11:00:00", "11:10:00", "11:20:00", "11:30:00", "11:40:00", "11:50:00", "12:00:00", "12:10:00", "12:20:00", "12:30:00", "12:40:00", "12:50:00", "13:00:00", "13:10:00", "13:20:00", "13:30:00", "13:40:00", "13:50:00", "14:00:00", "14:10:00", "14:20:00", "14:30:00", "14:40:00", "14:50:00", "15:00:00", "15:10:00", "15:20:00", "15:30:00", "15:40:00", "15:50:00"]

如何使用javascript检查每次是上午还是下午？

Answer 1

用: 分割字符串。将第一部分转换为数字，然后与 12 进行比较：

let data = ["09:00:00", "09:10:00", "09:20:00", "09:30:00", "09:40:00", "09:50:00", "10:00:00", "10:10:00", "10:20:00", "10:30:00", "10:40:00", "10:50:00", "11:00:00", "11:10:00", "11:20:00", "11:30:00", "11:40:00", "11:50:00", "12:00:00", "12:10:00", "12:20:00", "12:30:00", "12:40:00", "12:50:00", "13:00:00", "13:10:00", "13:20:00", "13:30:00", "13:40:00", "13:50:00", "14:00:00", "14:10:00", "14:20:00", "14:30:00", "14:40:00", "14:50:00", "15:00:00", "15:10:00", "15:20:00", "15:30:00", "15:40:00", "15:50:00"];

function checkAMorPM(time) {
  var hrs = Number(time.split(":")[0]);
  return (hrs >= 12 ? "PM" : "AM");
}

for(var i = 0; i < data.length; i++) {
  console.log(`${data[i]}: ${checkAMorPM(data[i])}`);
}

或者，如果您愿意，也可以在一行中完成：

const checkAMorPM = time => +time.split(':')[0] < 12 ? "AM" : "PM";

Answer 2

不用担心拆分值 - 只需使用 parseInt() 将其转换为数字 - 这只会将值（直到第一个非数字值）转换为一个数字然后可以对照 12 进行检查。

因此，因为字符“:”对于整数无效 - 只会解析前两个字符 - 这意味着“09:00:00”将被视为其“09”并解析为整数 9 和与 12 相比时 - 将消除“AM”。

let data = ["09:00:00", "09:10:00", "09:20:00", "09:30:00", "09:40:00", "09:50:00", "10:00:00", "10:10:00", "10:20:00", "10:30:00", "10:40:00", "10:50:00", "11:00:00", "11:10:00", "11:20:00", "11:30:00", "11:40:00", "11:50:00", "12:00:00", "12:10:00", "12:20:00", "12:30:00", "12:40:00", "12:50:00", "13:00:00", "13:10:00", "13:20:00", "13:30:00", "13:40:00", "13:50:00", "14:00:00", "14:10:00", "14:20:00", "14:30:00", "14:40:00", "14:50:00", "15:00:00", "15:10:00", "15:20:00", "15:30:00", "15:40:00", "15:50:00"];


data.forEach(function(item){
 parseInt(item, 10) < 12 
   ? console.log('AM')
   : console.log('PM')
})