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How to create QList of arrays

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  • B Offline
    B Offline
    BasicPoke
    wrote on last edited by
    #1

    Hello, I need to create a QList of arrays. Following is what I have come up with. Does this look ok? Should I call _delete _ here or not? Is there a shorthand for this other than the loop?

    @
    QList<unsigned short *>SplitData;
    unsigned short *pTemp;
    for( unsigned int j=0; j<NumGauges; j++ )
    {
    pTemp = new unsigned short[BufSize];
    SplitData.append( pTemp );
    delete pTemp;
    }@

    Thanks.
    Ron

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    • M Offline
      M Offline
      mcosta
      wrote on last edited by
      #2

      Hi,

      You shall NOT call delete because you're inserting in SplitData list only a pointer (not copy of data)

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      • B Offline
        B Offline
        BasicPoke
        wrote on last edited by
        #3

        Thanks mcosta. What if the above were inside a function, and the list SplitData were passed into the function. Would the list items still be available after the function returned? Or not since the pointers have gone out of scope?

        I should 'delete' each element later after I have used it, right? I suppose clearing the list will not take care of that.
        Ron

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        • SGaistS Offline
          SGaistS Offline
          SGaist
          Lifetime Qt Champion
          wrote on last edited by
          #4

          Hi,

          Depends on how you call the function. If you have a pointer that goes out of scope you loose the access to the memory segment you just allocated. In your case you have a copy of the pointer in your list so you still can access (and thus delete) it.

          qDeleteAll to the rescue :)

          Hope it helps

          Interested in AI ? www.idiap.ch
          Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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