Remote-processing CAMBASIC Uživatelský manuál stáhnout pdf (Strana 79)

Commands - 46

EXIT and EXIT CLEAR

Statement

SYNTAX: EXIT [line/label]

EXIT CLEAR

PURPOSE: To allow legal branching out of a loop structure.

REMARK S: Within FOR/ NEX T, GOSU B/RE TUR N and D O/U NTIL structures, it is sometimes necessar y to exit

the loop befor e the loop cond itions are m et.

EXIT C LEAR resets all stacks. It can be used in emergency stop (etc.) situations where the nesting

of loop structures cannot be known.

EXIT is always used with a line/label unless two or more levels are to be exited. When m ultiple

EXITs are used, the last one must have a line/label.

EXIT does not work in a DO/ENDDO structure.

EXAMPLE: 10 GOSUB 50

50 EXIT:GOTO 10

60 RETURN

Without the E XIT sta tement, the system w ould eventually crash, as the RE TUR N statem ent would

never be reached.

10 GOSUB 20

20 GOSUB 30

30 EXIT : EXIT 50

40 RETURN

50 GOTO 10

In this case there is a nested GOSUB structure. EXIT must be executed one time for each level of

nesting. F ailure to include two EXITs w ould have caused a stack imbalance on each pass.

Eventually, you would get a “Nesting” error message.

ERROR: < Can’t compile> – if line/label does not exist

< Syntax> – Trying to exit a non-recognized loop or structure

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Remote-processing CAMBASIC Uživatelský manuál Strana 79