indexing for() with an existing variable to change by a certain amount

Projects Programming
1

I have a variable, timePtr, that holds a location in the EEPROM as I step through it for sprinkler timing programs. I have also read runTimesThisProgram from the EEPROM.

I wish to loop starting at the current value, making exactly runTimesThisProgram passes.

I started with

for (timePtr; timePtr < timePtr + runtimesThisProgram;  ) {

In hindsight ( :o ), this never completes, as I observed running the loop. (I had the notion that the rhs of the termination condition would execute once.

I was surprised to find that

for (timePtr; timePtr < (unsigned int lastPass = (timePtr + runtimesThisProgram));  ) {

doesn't allow the creation of lastPass.

So I currently have

for (byte pass =0; pass<runtimesThisProgram; pass++  ) {
    ...
    byte timeNxt = EEPROM.read(timePtr++);                  //the runtime or first byte
    ...
}

This seems "clunky", and that it would be more readable if the initial line had all the information.

What is the "best" way to handle this kind of situation?

2

if you can tolerate runtimesThisProgram changing, then just use that as your counter through the loop

while( runtimesThisProgram-- ) {
  byte timeNxt = EEPROM.read(timePtr++);
}

If you can't, then you will have to assign it to some other variable.

3

That's just plain perfect . . . it's used to figure out how many passes to make in this loop, and as a factor in where the next program is located.

Thanks, greatly