Thanks for the help! I already know each integer takes 2 bytes. Thats 6 bytes for the ints and 2 bytes for the commas, 8 bytes.
On your 2nd point, SRAM might be larger, but remember your program is running in it. EEPROM on the other hand is all there for you to write data to, and you'd be able to store up to 341 of your 3 integer value sets before you ran out.
The EEPROM is 1024 bytes right? So 1024/8=128 value sets. I dont understand how you get 341, thats 1024/341=3.002 bytes? And I thought the SRAM because yes it has more space and you have to declare the size of an array at initialization anyway, so I can just see how much memory my sketch takes (slightly more than half) and then assign some (not all) of whats left for my array? Or would that slow down the processing or something?
Also as for recombining the integer values and adding the commas when writing to the SD... How would I temporarily store the information without commas? Woulden't using a two dimensional array use >= the memory of storing it as a string anyway for example? Or do you mean store it like 282355 then split it to 28,23,55 for writing to the SD?
Finally, you said create an array with filler characters presumably so that if it starts writing to the SD while writing to the EEPROM that the EEPROM data is saved to the SD card and then deleted up to the filler characters? Why not just check the data entry string length to see if its greater than 0? Since an empty string will be "", then it wont take up a character byte for an empty position in the array?
Sorry if I am misunderstanding you again, thanks for the input though.
edit: Is the playground link for writing the data bytewise? So thats how you can store the integer values without a comma? Does that mean its being written like this?
28 23 55 27 22 54 ? for two 3 int entries? Only in bytes?