I don't understand why the second example caches the src, checks if the current ...

iudqnolq on March 23, 2021 | parent | context | favorite | on: SvelteKit Is in Public Beta

I don't understand why the second example caches the src, checks if the current src matches the cached src, and if not sets both the src and the alt. Does the complier fully check the codebase to ensure they are always set together?