Side by side language files (array based vs. define based)

I know that ZenCart will be moving away from the original "define" based language files to the array based language files soon. But my question is, what happens when ZenCart (currently) finds both a define based file and an array based file in the same directory? Will this generate an error or is there an order of operations as to how language files are loaded?

No errors. If both older and newer style files exist, the older files are ignored, including their overrides.

https://docs.zen-cart.com/dev/langua...anguage_files/