Lookup

Lookup[assoc, key] looks up the value associated with key in the association. Lookup[assoc, key, default] returns default if the key is missing.

Examples

Look up values in an association:

assoc = <|"a" -> 1, "b" -> 2, "c" -> 3|>

Lookup[assoc, "b"]
(* 2 *)

(* With default value *)
Lookup[assoc, "missing", 0]
(* 0 *)

(* Multiple keys *)
Lookup[assoc, {"a", "c"}]
(* {1, 3} *)

Please visit the official Wolfram Language Reference for more details.