MATLAB: Does matlab create pointers to objects or create new copies

Question

I'm building a simple grid simulation, where my class contains . I want each to be able to keep track of which grid it is in, but I don't want to create 10,000 copies of the same for a 100 x 100 grid. Consider the following made up of

myGrid = cgrid(30, 20)
myGrid = 
  cgrid with properties:
    grid: {30×20 cell}
    M:    30
    N:    20

Now suppose I want each cell to know which grid it is in, so I can write functions for that extract useful information from the grid (i.e., findNeighbors)

%Snippet of cgrid constructor, modified for clarity
for ii = 1:myGrid.M
    for jj = 1:myGrid.N
       obj.grid{ii, jj} = ccell(ii, jj);       %Creates a ccell object and stores it at the location {ii, jj}                       
       obj.grid{ii, jj}.home = myGrid.grid          %Tells the ccell object where it lives
    end
end

Does this second line of the nested for loop create 600 copies of myGrid? Or does it just point to where myGrid is stored?

Because if I were to take any cell and modify its home, that wouldn't affect my original object of myGrid. It would seem so wasteful for a new object to be created everytime, but I know that somewhere somehow, obj.grid{1,2}.home is NOT the same object as myGrid.grid

Answer 1

See Comparison of Handle and Value Classes