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  • Dim, Redim At

    Two questions:

    1. Is it acceptable to REDIM...AT to a different AT address from the previous one?

    2. REDIM without an initial DIM sometimes won't compile. IS it OK to DIM without the AT qualifier then REDIM AT?

  • #2
    The code below shows yes, and yes to the 2 questions. I didn't have a problem compiling with REDIM only, have you got a code example that won't compile?
    Code:
    #COMPILE EXE
    #DIM ALL
    
    FUNCTION PBMAIN () AS LONG
    
        LOCAL myString AS STRING, ii AS LONG, ptrMyString AS BYTE PTR
        myString = SPACE$(5000000)
        ptrMyString = STRPTR(myString)
        FOR ii = 1 TO 5000000
           @ptrMyString = ii MOD 256 'long repeating string
           INCR ptrMyString
        NEXT
           
        REDIM a(1000000) AS LONG
        REDIM a(1000000) AS LONG AT STRPTR(myString)
        ? STR$(a(500000))
        REDIM a(1000000) AS LONG AT STRPTR(myString) + 500000
        ? STR$(a(500000))
    
    END FUNCTION
    Last edited by John Gleason; 10 Sep 2008, 05:17 PM. Reason: ii = 1 to 5000000, not 0 to 5000000

    Comment


    • #3
      Yes, you're probably right. It seemed to work for me too, but I got a bit suspicious of it after making a GPF go away by using an initial DIM. Next time I will keep the original code, so don't ask!

      The application has been rewritten without using a DIM/REDIMed array.

      I don't like arrays very much.

      Comment


      • #4
        REDIM without an initial DIM sometimes won't compile. IS it OK to DIM without the AT qualifier then REDIM AT?
        Code:
         FUNCTION Foo( params) as Something
        
          LOCAL  X() AS whatever
          ....
        .....
        .....
            REDIM X (number) AT address
        MCM
        Michael Mattias
        Tal Systems (retired)
        Port Washington WI USA
        [email protected]
        http://www.talsystems.com

        Comment


        • #5
          Explanation:
          Code:
          LOCAL  X() AS whatever
          Tells compiler, which reads top to bottom, "Whenever you see the symbol 'X' in this procedure it means an array of whatevers"

          NOte: you may need to physically place a REDIM statement prior to any use of X() in the procedure to avoid an 'array not dimensioned' error. (I never figured out the actual rules used). But that's easy enough...
          Code:
          FUNCTION Foo ( ......
           LOCAL X() AS whatever
           LOCAL  I, J, K AS LONG
           ...
          ' == END VARIABLE DECLARATIONS, START CODE  ====
            REDIM X(0) 
          
           ' REAL CODE STARTS HERE
          ....
          MCM
          Michael Mattias
          Tal Systems (retired)
          Port Washington WI USA
          [email protected]
          http://www.talsystems.com

          Comment

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