MissingQ

MissingQ[expr] gives True if expr has head Missing.

Examples

Test for Missing values:

MissingQ[Missing["NotAvailable"]]
(* True *)

MissingQ[Missing[]]
(* True *)

MissingQ[5]
(* False *)

Filter out missing values:

Select[{1, Missing[], 3, Missing["NA"]}, Not @* MissingQ]
(* {1, 3} *)

Please visit the official Wolfram Language Reference for more details.