Why does "dir" function return an n by 1 struct?

I am a novice at Matlab. I was reading about struct, and their size and that the size of a struct depends on the class of the value of the struct. If the struct values are not cells or if the cells are scalar, then the struct is 1 by 1. https://uk.mathworks.com/help/matlab/ref/struct.html

But when I look at the documentation for the 'dir' function: https://uk.mathworks.com/help/matlab/ref/dir.html?searchHighlight=dir&s_tid=doc_srchtitle

It says the class type in the struct are char, double and logical.

I looked at the class types documentation: https://uk.mathworks.com/help/matlab/matlab_prog/fundamental-matlab-classes.html

So these are their own class types, they are not cells, so why is the struct an n by 1 struct and not a scalar struct?

Answer 1

[Matt J]

If the struct values are not cells or if the cells are scalar, then the struct is 1 by 1.

The link you have cited applies specifically to inputs to the struct() command, when used to create MATLAB structure a array variables. The dir() command has its own rules.

The bottom line is, there is no connection between the dimensions of a struct array and the field data it contains. I could manually build a struct array of any dimensions regardless of whether its fields are cells, scalars, or whatever. Example:

      >> s(2).cell={1,2,3,4}; s(1).scalar=5

       s = 

          1×2 struct array with fields:

            cell
            scalar

[Pa342]

I see, thanks!