Sub

CommandFlow control

sub {name}
...
return [value]

sub starts a sub: a named group of lines that gosub runs, ending with return. Parameters passed by gosub are in %1, %2, … and their number is in %0.

gosub say hello world
halt

sub say
  display ok %0 words: %1 %2
return

Where to put subs

When the normal flow of the script reaches a sub line, it does not run the sub: it jumps over it, to the line after the sub’s first return. A sub with an early return, such as one inside an if, is therefore not skipped completely: the script lands in the middle of it. Two ways to avoid that:

Put the subs after the main part of the script, after its halt or its final goto, where the flow never reaches them. This is the usual layout.
Or wrap the body in a block right after the sub line. The script then skips the whole block:

sub check
{
  if %x = 0
    return 0
  return 1
}

set %x 0
gosub check
display ok #Result         ; 0
halt

Details

Names are not case-sensitive. When two subs have the same name, gosub uses the last one in the script.
Leave a sub with return, never with goto.

See also

Based on the EasyUO wiki, edited for EasyUO Reforged. This text is available under the GNU Free Documentation License 1.2.