Java arrays (not sure if this question is advanced)

[aga010607]

For design convenience I need to implement an attribute in a superclass as

double[][] myArray2D = new double[M][N]

which is used in most subclasses with M>>1 and N>>1. However, a couple of subclasses only require

double[][] myArray2D = new double[1][N]

or

double[] myArray1D = new double[N].

Is there a difference in memory allocation and in computational efficency between implementing myArray1D[N] and myArray2D[1][N]??

Thank you. AGA

[r035198x]

For design convenience I need to implement an attribute in a superclass as

double[][] myArray2D = new double[M][N]

which is used in most subclasses with M>>1 and N>>1. However, a couple of subclasses only require

double[][] myArray2D = new double[1][N]

or

double[] myArray1D = new double[N].

Is there a difference in memory allocation and in computational efficency between implementing myArray1D[N] and myArray2D[1][N]??

Thank you. AGA

say you have a constructor

SuperClass(int M, int N ) {
    myArray2D = new double[M][N];
     ...

then the other classes simply do

ChildClass(int N) {
   super(1, N);

You only declare slots that you need.