区别as.POSIXct /。POSIXlt和strptime用于将字符向量转换为POSIXct/POSIXlt

I have followed a number of questions here that asks about how to convert character vectors to datetime classes. I often see 2 methods, the strptime and the as.POSIXct/as.POSIXlt methods. I looked at the 2 functions but am unclear what the difference is.I have followed a number of questions here that