Difference between writing something on one line and on several lines

Question

Where is the difference when I write something on one line, seperated by a , and on two lines. Apparently I do not understand the difference, because I though t

Answer 1

At the first case, the commands

a, b = b, a + b;

will do first the sum a + b and then will do the assignment. In that case, b always contains 1. This explains why the final result is 6, because you are adding 1 six times.

The second code you posted its correct.