about write in file

Hi everyone: I have a exist file named as 'data.txt', and I want to write data into the file in every loop; but the update data always overwrite on the previous, how can I avoid this problem and write data in file as the size of n*2; my code as follow: the size of matrix h is n*2;

for i = 1 : 10
   fid = fopen('data.txt','w+');
   fprintf(fid,'%d\n',h(i,:));
   fclose(fid);
end

Thank you so much!

Answer 1

[Walter Roberson]

for i = 1 : 10
   fid = fopen('data.txt','at');
   fprintf(fid,'%d\n',h(i,:));
   fclose(fid);
end

Answer 2

[Azzi Abdelmalek]

fid = fopen('data.txt','w+');
for i = 1 : 10
    fprintf(fid,'%d\n',h(i,:));
end
 fclose(fid);