Editing Oz (programming language) (section)

====Procedures====
Functions in Oz are supposed to return a value at the last statement encountered in the body of the function during its execution. In the example below, the function Ret returns 5 if X > 0 and -5 otherwise.
<syntaxhighlight lang="erlang">
declare
fun {Ret X}
   if X > 0 then 5 else ~5 end
end
</syntaxhighlight>
But Oz also provides a facility in case a function must not return values. Such functions are called procedures.<ref>{{Cite web|url=https://mozart.github.io/mozart-v1/doc-1.4.0/tutorial/node5.html#control.procedure|title = 5 Basic Control Structures}}</ref> Procedures are defined using the construct "proc" as follows
<syntaxhighlight lang="erlang">
declare
proc {Ret X}
   if X > 0 then {Browse 5} else {Browse ~5} end
end
</syntaxhighlight>
The above example doesn't return any value, it just prints 5 or -5 in the Oz browser depending on the sign of X.