null coalescing operator (
??) has been added as syntactic sugar for the common case of needing to use a ternary in conjunction with
It returns its first operand if it exists and is not
NULL; otherwise it returns its second operand.
Coalesce returns the first none null argument from a set of arguments. Only the first non null argument is return, all subsequent arguments are ignored. The function will evaluate to null if all arguments are null.