Pulling Variables from SD card to be used in void loop()

I am trying to pull variables from a SD card that can be used in other operations that exist inside of my void loop. I attached a very simple sketch where I pull the variable “a” from my SD card. Ideally I would be able to then use that variable in places other than void setup.

I am very inexperienced with Arduino and I recently started my graduate program(in ME) but it turns out my thesis is going to be 90% Arduino programming. Any help would be much appreciated!

Trouble_shooting.ino (686 Bytes)

This is the same question as your other post - see the response to that.