Hello, good day.
Exercise: Null and Undefined
Observation: There appears to be a link that was repeated twice, in the first place it wasn’t formatted and it oddly stands alone.
1. undefined, MDN. (2021). https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/undefined (accessed June 4, 2021). ↩
This is a citation, of the kind you can find in papers and books.
It could have been a link embedded in the text as well. Like I’ve done above with “citation”.
Those links below are a separate thing, they don’t need to map directly to anything in the text and are intended as complementary/suplementary sources.