React attached all its listeners to document, which is why two React versions on one page could not coexist and why mixing React with anything else was fragile.…
3.7 shipped in November with optional chaining, which had been the most-requested feature for years and which replaces a specific and very common defensive pattern. The distinction from…
|| falls through for every falsy value, so a default applied with it overrides a legitimate zero, an empty string and false. The third line is the one…
3.7 shipped optional chaining in November and the objection got smaller. allowJs, checkJs and a per-file opt-in — and strictNullChecks, which is the flag that pays.
The editor re-runs save() on load and compares the result with what is stored in the post. Any difference is a validation error, and the block offers to…
Anything an effect starts — a subscription, a timer, a fetch, an event listener — outlives the component unless the effect returns something that stops it. The cleanup…
It is documented alongside DOM access and its more interesting property is that it is a mutable container whose identity survives every render and whose changes do not…
A JavaScript dependency without types is an implicit any, and under noImplicitAny it is a compile error — so the choice is a declaration or a suppression. Describing…