ES2021 edition of “JavaScript for impatient programmers”

impatient-js-es2021.md

What is new in the ES2021 edition of “JavaScript for impatient programmers”?

Free to read online: exploringjs.com/impatient-js/

• The exercises now run as native ESM modules on Node.js. Previously, they were run via the esm package.
• Material on new ES2021 features:
  • String.prototype.replaceAll()
  • Promise.any()
  • Logical assignment operators
  • Underscores (_) as separators in number literals and bigint literals
• New chapter: “New JavaScript features” lists what’s new in each release after ES6.
• Describing some features in more detail:
  • ES2019: New section on optional catch binding
  • ES2019: New section on Symbol.prototype.description
  • ES2018: New section on the template literal revision
  • ES2018: New section on Promise.prototype.finally()
  • ES2017: New section on trailing commas in function parameter lists and calls
• Rewrite of chapter “Callable values”:
  • Moved content on dynamic code evaluation into its own chapter.
  • Improved coverage of this
  • And more
• Rewrite of chapter “Single objects”:
  • Improved coverage of this
  • Explaining the function methods .call(), .apply(), .bind()
• Chapter on symbols:
  • Mostly new section “Symbols are primitives that are also like objects”
  • New section “The descriptions of symbols”
  • Major rewrite of section “Symbols as unique property keys”
• Chapter on regular expressions:
  • Much improved section “The flags /g and /y, and the property .lastIndex”