Dynamic 2 dimensional array with new?

This is a discussion on Dynamic 2 dimensional array with new? within the C++ Programming forums, part of the General Programming Boards category; I want to create a dynamic 2 dimensional array like this Code: parray = new z[x][y]; Why dosen't new allow ...

  1. #1
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    Dynamic 2 dimensional array with new?

    I want to create a dynamic 2 dimensional array like this
    Code:
    parray = new z[x][y];
    Why dosen't new allow this? shouldn't it be possible for new to allocate memory the size of x*y and return a pointer to z[0][0]?

  2. #2
    Bond sunnypalsingh's Avatar
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    Example of 2D memory allocation
    Code:
    int **ptr;
    ptr=new int *[10];//creates an array pointer
    for(int i=0;i<10;i++)
    p[i]=new int [5];//creates space for each row
    make sure u delete the mempry after use

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    thanx

  4. #4
    Frequently Quite Prolix dwks's Avatar
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    To delete that memory:

    Code:
    for(int i=0;i<10;i++)
        delete p[i];
    delete [] p;
    dwk

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  5. #5
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    Not quite. Should be:
    Code:
    for(int i=0;i<10;i++)
        delete [] p[i];
    delete [] p;

  6. #6
    Bond sunnypalsingh's Avatar
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    I think what dwks is saying is right

  7. #7
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    >> delete [] p[i];

    nice catch

  8. #8
    Bond sunnypalsingh's Avatar
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    yes...it should be
    Code:
    delete[] p[i];

  9. #9
    Frequently Quite Prolix dwks's Avatar
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    Oops. Yes.
    Code:
    delete [] p[i];
    dwk

    Seek and ye shall find. quaere et invenies.

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  10. #10
    xhi
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    Sometimes oops just isnt good enough.

    maybe oops[100] would do.

  11. #11
    Frequently Quite Prolix dwks's Avatar
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    Perhaps you were thinking of [50]. 10*5 = 50.
    dwk

    Seek and ye shall find. quaere et invenies.

    "Simplicity does not precede complexity, but follows it." -- Alan Perlis
    "Testing can only prove the presence of bugs, not their absence." -- Edsger Dijkstra
    "The only real mistake is the one from which we learn nothing." -- John Powell


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