1. ZPL II, ZBI 2, Set-Get-Do, Mirror, WML Programming Guide
  2. ZBI Commands
  3. GOTO/GOSUB
  • ZPL II, ZBI 2, Set-Get-Do, Mirror, WML Programming Guide
GOTO/GOSUB

GOTO/GOSUB

GOSUB
 is followed by a line number. The program will attempt to process the line the
GOSUB
 command points to rather than the next line of the program. Upon executing the
GOSUB
 statement, the interpreter continues running at the line number specified following
GOSUB
. If the line number referenced does not exist, an error will occur.
Before executing the next line, the
GOSUB
 command stores the line number of the
GOSUB
 line. When the
RETURN
 statement is called, the program moves back to the next line following the
GOSUB
.
Executing a
RETURN
 statement without a corresponding
GOSUB
 statement causes an error.
GOSUB
 statements can be nested.
GOTO
 works the same way as
GOSUB
 except that no return address will be stored.
Format
GOSUB <A>
RETURN
GOTO <A>
Parameters
<A>
 = the program location executed immediately after the GOTO or GOSUB.
Example
This is an example of how to use the
GOSUB
 command:
10 PRINT "Call Subroutine" 
20 GOSUB 1000 
30 PRINT "Returned from Subroutine" 
40 END 
1000 PRINT "In Subroutine" 
1010 RETURN
Example
This is an example of how to use the
GOTO
 command:
10 PRINT "Prepare to Jump!" 
20 GOTO 1000 
30 PRINT "Jump Missed..." 
1000 PRINT "Jump Successful" 
1010 END
Comments
These are program commands and must be preceded by line numbers.