nt index = 0;
its initial value is 0 not garbage I am switching from 0 to 1 thats what is written in there.
Where? Here?
int index,i = 0;
That is creating two variables, index and i, and assigning i an initial value of 0. index does NOT get assigned an initial value.
I think it is setting the character array to null so no garbage is in it.
No. It is assigning only pressure[0] a value.
Comma does NOT mean "do this to all these variables...".