JavaScript technologies overview
Lexical grammar
JavaScript data structures
Enumerability and ownership of properties
Iteration protocols
Strict mode
Transitioning to strict mode
Template literals
Deprecated features
https://developer.mozilla.org/en-US/docs/Web/JavaScript/JavaScript_technologies_overview
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Lexical_grammar
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Enumerability_and_ownership_of_properties
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Strict_mode
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Deprecated_and_obsolete_features