Switch

Switch[expr, form1, value1, form2, value2, ...] evaluates expr, then returns the value corresponding to the first matching form.

Examples

Switch on value:

Switch["b",
  "a", 1,
  "b", 2,
  "c", 3
]
(* 2 *)

With default:

Switch[5,
  1, "one",
  2, "two",
  _, "other"
]
(* "other" *)

Please visit the official Wolfram Language Reference for more details.