Question

该if语句当前将变量与静态数进行比较，如果它们相等，则为settime7变量提供一个十六进制数，用于将时间发送给单位。

是否可以缩短此if语句：

if(timeM == 0){
   settime7 = 0x00;
}
else if(timeM == 1){
   settime7 = 0x01;
}
else if(timeM == 2){
   settime7 = 0x02;
}
else if(timeM == 3){
   settime7 = 0x03;
}
// ...and so on to timeM == 60 and settime = 0x3C.

Answer 1

只需分配变量：

val window = org.apache.spark.sql.expressions.Window.orderBy("hourTimestamp")
val weatherUpdate = df
                    .withColumn("WeatherLag1", lag("Weather", 3).over(window))
                    .withColumn("WeatherLag2", lag("Weather", 6).over(window))
                    .withColumn("WeatherLag3", lag("Weather", 9).over(window))
                    .withColumn("Weather",coalesce($"Weather",$"WeatherLag1",$"WeatherLag2",$"WeatherLag3"))

是否将自己写为十进制或十六进制对于存储的整数都无关紧要。

Answer 2

如果我很了解你想要

...
else if(timeM == 60){
   settime7 = 0x60;
}

然后：

settime7 = (timeM / 10) * 16 + (timeM % 10)

我可以缩短这个if语句吗？

2 个答案: