CLEAR command

[TerryRitchie]

I dony' understand. Look at this code:

Code: (Select All)

'DIM SHARED b%(30) 'if activated, the program doesn't work.

REDIM SHARED b%(30) 'if activated, the program works.

'if both deactivated, the program doesn't work. 

CLEAR

FOR i% = 1 TO 40

    REDIM _PRESERVE b%(i%)

    b%(i%) = i%

NEXT i%



CALL ciao



SUB ciao

    PRINT b%(3)

END SUB

So, if CLEAR completely remove b%(), so that it doesn't exist anymore, why it is however needed REDIM SHARED b%(30) before CLEAR? It seems that CLEAR completely remove b%(), without removing the information that it is SHARED. But how is it possible that an inexistent array could be SHARED?

In this example a dynamic array is created ( b%() ) and then immediately removed with CLEAR. However, inside the loop the dynamic array is once again created when i% equals 1 and then increased in size when i% is greater than 1. See below. Your code actually creates b%() twice, not once to be reused.

Code: (Select All)

' here the code is creating a dynamic array of 31 indexes all with a value of 0

REDIM SHARED b%(30) 'if activated, the program works.

' CLEAR will now remove this dynamic array

CLEAR

' this loop will create a new dynamic array at first and then populate it

FOR i% = 1 TO 40

    ' when i% = 1 the code creates a new instance of b%() with a dimension of 1 ( b%(1) )

    ' when i% > 1 the code resizes the existing array ( b%(i%) ) and preserves the data previously inserted

    REDIM _PRESERVE b%(i%)
    b%(i%) = i%
NEXT i%

CALL ciao

SUB ciao
    PRINT b%(3)
END SUB