A function that updates the input

Very basic question. Can I define a function that updates a matrix A with another entry B. That is

function A=Update(A,B)

?

Answer 1

[Walter Roberson]

Yes, provided that the array to be updated is an output as well as an input, and provided that the user assigns the output on top of the same array. For example,

pqr = randi(5,2,3);
rst = randi([-2 2], 2, 3);
pqr = Update(pqr, rst);

function A = Update(A,B)
  A = A+B;
end

However, what you cannot (typically) do is something like

pqr = randi(5,2,3);
rst = randi([-2 2], 2, 3);
Update(pqr, rst);

and expect that pqr will be changed by the Update function. It is not always impossible, but it is not good programming.