how to merge multiple csv files (or xlsx files)

Hi,

I have here, for example two csv files need to merge(merge into one). Can anyone kindly help how to merge them. Many thanks in advance.

Answer 1

[Walter Roberson]

fout = fopen('mergedData.csv', 'wt');

in_filenames = {'previouData.csv', 'currentData.csv'};
for K = 1 : length(in_filenames)
  thisfile = in_filenames{K};
  fin = fopen(thisfile, 'rt');
  while true
    thisline = fgetl(fin);
    if ~ischar(thisline); break; end   %end of file
    if ~isempty(thisline);  %assume empty lines are trailing empty lines
      fprintf(fout, '%s\n', thisline);
    end
  end
  fclose(fin);
end

fclose(fout);

Under some circumstances you can use much shorter code: you would need to be sure that the csv files were consistent about whether they used newline only or else carriage return + newline; and you would need to know that each file ended with a line terminator. The code I have given here is as long as it is because I do not assume that the line terminators are consistent and I do not assume that there is a line terminator at end of file.

[Mekala balaji]

Sir/Madam,

I do not get any output of merged data.

Best regards,

[Walter Roberson]

I have edited to correct a mistake.

[Mekala balaji]

I still not getting any output. May I ask in which variable the final output(merged data) is saved.

[Walter Roberson]

It is not saved in a variable, it is saved in the file mergedData.csv as you asked to merge the files, not to read the files into memory.