How can I save data to a .mat file the variables of the old .mat files aren't lost after saving new ones?

In my program, I need to save variables in each for loop and I want to save all variables after run all for loops in file result.mat. Howerver, when I save new variables, variables in previous for loop are lost. How can I save all data after finishing all for loop? Thank for your help!

Answer 1

[Azzi Abdelmalek]

Use append option

a=10;
save('file','a')
b=20;
save('file','b','-append')