Special symbols
@ I mentioned earlier at the beginning of the string used to escape in free, to write a string of what is what, encountered \no escape
?? a value is not determined null, then a default value becomes later, if it is not the original value
$ String beginning tampering and formateffect similar format string, the type of conventional type and are anonymous, {} which is variable or method able to turn into string or other expression
in square brackets which a write is to take two layer and the contents inside the square brackets, no tampering.
: String of formatted
The time format into the format you want