Null

Null is a symbol used to indicate the absence of an expression or a result. When it appears as a complete output expression, no output is printed.

Examples

Suppress output:

x = 5; (* returns Null, nothing printed *)

Explicit Null:

{1, Null, 2, Null, 3}
(* {1, Null, 2, Null, 3} *)

Please visit the official Wolfram Language Reference for more details.