*.* and %s meaning in MATLAB

what does these symbols mean in MATLAB

*.* and %s 

Answer 1

[DGM]

In an expression like

v = 'words';
fprintf('this is a progression of several %s\n',v)

%s specifies "string or character vector".

In an expression like

fname = uigetfile('*.*')

'*.*' refers to any file -- or at least any file with a dot in the middle of its full name. The asterisk is a wildcard.