As far as I know, xlsread can potentially read all of them, provided they’re in Excel format. (The xlsread funciton calls Excel.) If you want to specifically select xlsread or csvread on the basis of the file extension, something like this would work:
filext = {'xls' 'xlsx' 'csv'};
fnm = inputdlg('Enter the full name (+ext) of your file: ');
ext = regexpi(fnm, '[.]?','split');
filtyp = find(strcmpi(ext{:}(2),filext));
followed by a switch-case block to call the appropriate function based on the output in ‘filtyp’, and passing to it the full ‘fnm’ file name.
