EXIT

Description

This command is used to exit a loop or procedure before its real end.

Syntax

1. EXIT FOR
2. EXIT WHILE
3. EXIT DO
4. EXIT FUNCTION
5. EXIT SUB

Hints

There are examples, then exiting loops (FOR, DO, WHILE) improperly (that is, with GOTO) corrupts JB stack, leading to unexpected behavior.

Exit function/exit sub provides a nice way to finish long muli-step check then one step is failed. See example.

Example

Also see individual commands under Looping and Procedures for examples:

• FOR..NEXT
• WHILE..WEND
• DO..LOOP
• FUNCTION
• SUB

Example: using exit function to abort long multi-step check.

data "00:00"
data "1:23"
data "12:34"
data "100:00"
data ":00"
data "1:00"
data "1:0"
data "1:-0"
data "1:-1"
data "1a:2b"
data "a:bc"
data "25:00"
data "21:60"
data "'''*"

read t$
while t$ <>"'''*"
    print t$, tminutes$(t$)
    read t$
wend

end

function tminutes$(tpoint$)
'Find total minutes from strict HH:MM input
'strict format check
'returns "InvalidTime" for wrong input
    tminutes$="InvalidTime"    'assume exit function will show fail
    'hours
    hh$=trim$(word$(tpoint$, 1, ":"))
    'check lengths
    if len(hh$)>2 then exit function
    'check numbers
    if instr("0123456789", mid$(hh$,1,1))=0 then exit function
    if len(hh$)>1 then
        if instr("0123456789", mid$(hh$,2,1))=0 then exit function
    end if
    'check range
    hh=val(hh$)
    if hh>23 then exit function

    'same for minutes
    mm$=word$(tpoint$, 2, ":")
    if len(mm$)<>2 then exit function
    if instr("0123456789", mid$(mm$,1,1))=0 then exit function
    if instr("0123456789", mid$(mm$,2,1))=0 then exit function
    mm=val(word$(tpoint$, 2, ":"))
    if mm>59 then exit function

    'if we got here, that means all OK
    tminutes$=str$(hh*60+mm)
end function

Useful Procedures

' Place a useful function or sub using this keyword here