Hallo, Is it possible, that I can add the strings '1' '.' and '2'. I want to add this 3 strings: 1.2 and convert it into a float value and than I want add a float value.
Have you even looked at the descriptions of the two functions I mentioned ?
You cannot "add" strings (at least in C. Maybe in BASIC or something). You concatenate them. That's what strcat() (from string.h) does.
atof() converts a string to a floating point number.