Vector question

This is a discussion on Vector question within the C++ Programming forums, part of the General Programming Boards category; Hello, I have created a vector of pointers. If I resize my vector, will it be filled in with NULL ...

  1. #1
    Registered User
    Join Date
    Feb 2010

    Vector question

    Hello, I have created a vector of pointers.
    If I resize my vector, will it be filled in with NULL values?
    Or will it point to garbage? If it will point to garbage, how do I init them on NULL?

    vector< vector< Tile*> > board;
    for (int i = 0; i < size; i++)
    This does not work because I am pointing to the values:

         for(int i =0; i < size; i++)
             for(int j=0; j < size; j++)
                 board[i][j] = NULL;
    Thank you

  2. #2
    Registered User
    Join Date
    Nov 2010


    You could try using the push_back() method, and I know that int vectors are set to default value of 0, so maybe?

  3. #3
    neptune whiteflags's Avatar
    Join Date
    Apr 2006
    United States
    You should be supplying the other argument to resize()

    board[i].resize(size, NULL);

  4. #4
    Join Date
    Oct 2007
    I believe that if you resize a vector, all of the values will be default-constructed, so that would mean NULL, yes.
    However, whiteflags has a point. You shouldn't be using resize anyway, unless you have a very specific requirement. Use push_back, and if possible, don't use pointers.
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    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

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