JavaScript · Module 5
Answers and explanations · Model events with arrays and objects
Compare these references after your own attempt. You can read them at any time; they do not record a live model or vendor run.
JavaScript · Module 5
Compare these references after your own attempt. You can read them at any time; they do not record a live model or vendor run.
A: it reads the first event object's id. An unsuccessful find returns undefined; accessing undefined.title throws a TypeError. Test whether a record was found before using it.
B:
const available = events.filter((event) => {
return event.places > 0;
});
Without return, the callback returns undefined, so no record qualifies. Parentheses-only arrow expressions return implicitly, but braces-based bodies need return.
C:
function creativeTitles(events) {
return events
.filter((event) => event.category === "creative" && event.places > 0)
.map((event) => event.title);
}
The first operation selects records; the second transforms each selected record to a title. Empty input gives []. A creative event with zero places is excluded. This code does not write into any record, though filtered arrays still refer to the same objects.