Problem Statement

List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions. Common conditional structures include if-then-else and switch. Less common are arithmetic if, ternary operator and Hash-based conditionals. Arithmetic if allows tight control over computed gotos, which optimizers have a hard time to figure out.

Let's start with the solution:

if a eq 5 then print, "a equals five" [else print, "a is something else"]

if a eq 5 then begin
  ... some code here ...
endif [else begin
  ... some other code here ...
endelse]

case  of
  (choice-1): 
  [(choice-2):  [...]]
  [else: ]
endcase

switch  of
  (choice-1): 
  [(choice-2):  [...]]
  [else: ]
endswitch

on_error label