undefined - JavaScript | MDN
The undefined global property represents the primitive value undefined. It is one of JavaScript's primitive types.| MDN Web Docs
The undefined global property represents the primitive value undefined. It is one of JavaScript's primitive types.| MDN Web Docs
Baseline identifies the availability of web platform features across popular browsers, including APIs, CSS properties, and JavaScript syntax. Baseline describes web features as being either widely available or newly available. Features that do not meet the Baseline criteria are said to have limited availability.| MDN Web Docs
The Set object lets you store unique values of any type, whether primitive values or object references.| MDN Web Docs
V8#| nodejs.org
