Although there was an early attempt to reconcile ECMAScript 3.1 and ECMAScript 4, this ultimately failed as the two camps had difficulty with the very different perspectives on how the language should grow.
In 2008, Brendan Eich, the creator of Java Script, announced that TC-39 would focus its efforts on standardizing ECMAScript 3.1.
ECMAScript 4 was massive in scope, introducing changes both small and large to the language.
Updated features included new syntax, modules, classes, classical inheritance, private object members, optional type annotations, and more.
This book is not for beginners who have never written Java Script.
Work then began on ECMAScript Harmony, with ECMAScript 6 being the first standard released in this new “harmonious” spirit.
The “3.1” was intended to show that this was an incremental change to the existing standard.
ECMAScript 3.1 introduced very few syntax changes, instead focusing on property attributes, native JSON support, and adding methods to already-existing objects.
The scope of the ECMAScript 4 changes caused a rift to form in TC-39, with some members feeling that the fourth edition was trying to accomplish too much.
A group of leaders from Yahoo, Google, and Microsoft created an alternate proposal for the next version of ECMAScript that they initially called ECMAScript 3.1.
Chapter 5: Destructuring for Easier Data Access introduces object and array destructuring, which allow you to decompose objects and arrays using a concise syntax.