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    Multidimensional array of vectors?


    Hello,

    I'm new to Java, and I am struggling to create the following data structure. I am trying to create a 3d array of vectors. Basically I have 10 x,y,z coordinates forming a 10x10x10 grid. For each possible square I require a vector giving a list of items present in that particular square.

    So far I have this:
    Code:
    //declaration
        protected Vector<myItems>[][][] position;
    
    //usage
    	position[i][j][k].add(new myItems(x,y,z));
    I'm getting a null pointer exception when trying to add items to the vectors. I'm guessing this is because I haven't allocated memory for 'position' yet, but I'm struggling to do so.

    Would anyone be able to give me a hint?

    Cheers
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  3. Daniel Schildsky
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    Use ArrayList instead of Vector


    Vector is an old counterpart of ArrayList, which is a synchronised implementation. Use an ArrayList instead.

    Like any other objects, you need to instantiate an instance of ArrayList before you could add data into the instance.

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    • codeJ agrees
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