Every six weeks, we create a new branch of V8 as part of our release process. Each version is branched from V8’s Git master immediately before a Chrome Beta milestone. Today we’re pleased to announce our newest branch, V8 version 9.4, which is in beta until its release in coordination with Chrome 94 Stable in several weeks. V8 v9.4 is filled with all sorts of developer-facing goodies. This post provides a preview of some of the highlights in anticipation of the release.

JavaScript #

Class static initialization blocks #

Classes get the ability to group code that should run once per class evaluation via static initialization blocks.

class C {
  // This block will run when the class itself is evaluated
  static { console.log("C's static block"); }
}

Starting in v9.4, class static initialization blocks will be available without a need for the --harmony-class-static-blocks flag. For all the detailed semantics around the scoping of these blocks, please see our explainer.

V8 API #

Please use git log branch-heads/9.3..branch-heads/9.4 include/v8.h to get a list of the API changes.

Developers with an active V8 checkout can use git checkout -b 9.4 -t branch-heads/9.4 to experiment with the new features in V8 v9.4. Alternatively you can subscribe to Chrome’s Beta channel and try the new features out yourself soon.