textContent parses HTML innerHTML parses its value as HTML (an XSS risk with untrusted data); textContent treats it as plain text innerHTML escapes all tags They are identical
It makes a deep copy of everything It makes a shallow copy: a new array, but the same object references inside it It makes b a reference to a It copies only the first element
Removing all listeners Assigning events to another developer Attaching one listener to a parent element and handling events from its children through bubbling, using event.target Firing events on a timer
undefined A single accumulated value The original array, modified in place A new array with the callback's result for each element; the original array is unchanged
It is a JavaScript runtime built on V8 that uses an event-driven, non-blocking I/O model, mainly for server-side code It is a browser It is a front-end CSS framework It runs only in Chrome
