Question

我不明白这行代码。有人可以逐字逐句解释第4行的含义吗？

hour = Math.floor(nextArrival / 3600);
min = Math.floor(nextArrival % 3600 / 60);
sec = Math.floor(nextArrival % 3600 % 60);
nextArrivalFinal2 = ((hour > 0 ? hour + ":" + (min < 10 ? "0" : "") : "") + min + ":" + (sec < 10 ? "0" : "") + sec);

如何编写它，以便在新的一天和时间为00:00:00时，它仍会显示小时所在的00。目前，第4行中的代码跳过显示小时数，如果我认为是在1以下。所以如果时间是00:05 AM，它将只显示分钟和秒而不是00小时。

Answer 1

Its called a ternary operator

Syntax:

(expression) ? true part : false part

This is more verbose approach for your line 4

var nextArrivalFinal2 = ""
if (hours > 0) {
  nextArrivalFinal2 = hour + ":";
  if (min < 10)
    nextArrivalFinal2 += "0"
  else
    nextArrivalFinal2 += ""
} else {
  nextArrivalFinal2 += "";
}

nextArrivalFinal2 += min + ":";
if (sec < 10)
  nextArrivalFinal2 += "0"
else
  nextArrivalFinal2 += "";
nextArrivalFinal2 + sec

Answer 2

This line is using the Conditional Operator

condition ? expr1 : expr2

Using only if and else this would give something like this

if(hour > 0){
    text = hour + ":";  
    if(min < 10){
        text += "0"
    }else{
        text += ""
    }
    text += "";
}
text += min + ":";
if(sec < 10){
    text += "0";
}else{
    text += "";
}
text += sec;

Obviously there are useless else but I still show them to use every term of the conditional operator.

Answer 3

The others have explained line 4 very well, but for the last part of your question, you want something like consistent formatting as hh:mm:ss ?

nextArrivalFinal2 = (hour < 10 ? "0" : "") + hour + ":" + (min < 10 ? "0" : "") + min + ":" + (sec < 10 ? "0" : "") + sec;

Answer 4

//示例nextArrival = 3760（这是以秒为单位的实际时间） //小时给你的小时数：1小时= 3600秒

hour = Math.floor(nextArrival / 3600);

//获取分钟数：nextArrival % 3600将为您提供删除小时数的秒数

min = Math.floor(nextArrival % 3600 / 60);

//这会给你秒数

sec = Math.floor（nextArrival％3600％60）;

// nextArrivalFinal2 =（（小时> 0？小时+“：”+（小于＆lt; 10？“0”：“”）：“”）+ min +“：”+（秒<10？“0”：“ “）+ sec）;

您必须了解三元运算符这是一个基本的三元运算符 a＆gt; b？ a：b;

如果a大于b，则取a，否则取b;

同样，在这种情况下，如果hour>0它会打印hour + some other values of minnutes which also have a ternary operator其他“”，如下面代码第10行所述。
之后，他们是一个+，这意味着附加到一个字符串。那么它将打印min的值，如第12行所示+某个sec值，它将再次成为一个三元运算符最后它将在第17行打印sec ((hour > 0 ? hour + ":" + (min < 10 ? "0" : "") : "") + min + ":" + (sec < 10 ? "0" : "") + sec)

此时间转换的语法解释

4 个答案:

Syntax: