What is [] to the left of "=" means?

[processed_I] = preA(handles, connected_I, 0);

Hi, is that the [] to the left of "=" means matrix? For example, if the function return a matrix of 3X3, so the left [] will get the matrix of 3X3 too? Thanks

Answer 1

[Daniel Shub]

In this case the [] does not mean anything

EDIT

[processed_I] = preA(handles, connected_I, 0);

and

processed_I = preA(handles, connected_I, 0);

mean the same thing. However

[processed_I processed_J] = preA(handles, connected_I, 0);

and

[processed_I, processed_J] = preA(handles, connected_I, 0);

are the same while

processed_I processed_J = preA(handles, connected_I, 0);

is invalid and

processed_I, processed_J = preA(handles, connected_I, 0);

mean something totally different. On the LHS of an assignment, the [] are used to denote that multiple outputs are expected such that the first output of a function is placed into processed_I and the second is placed into processed_J.

[Superb]

Means it's same with or without [] to the left of "="? Then what case will have different meaning?

Example below, is this will have different meaning? Thanks :)

[processed_I processed_J] = preA (handles, connected_I, 0);

[Superb]

Thanks Daniel, now I understand it more,

for this code,

processed_I, processed_J = preA(handles, connected_I, 0);

is it valid or not?

and for the LHS things you mean, how can we know which output will be put into processed_I, and which output will be put into processed_J?

[Jan]

It is trivial to check the validity of the code by your own - simply try it in Matlab.

"processed_I" will be the first output, "processed_J" the second one. The order of outputs is defined in the function header. A function defined by:

function [a, b] = fcn(c, d)

receives e.g. c as first input and replies b as second output.

These basics are explained exhaustively in the Getting Started chapters. It is recommended for all users to read them.