The following is a changelog for JavaScript 1.8.1. This version was included in Firefox 3.5.
JavaScript 1.8.1 is a modest update syntactically to JavaScript; the main change in this release is the addition of the Tracemonkey just-in-time compiler, which improves performance.
New features in JavaScript 1.8.1
Object.getPrototypeOf()- Support for native JSON
String.prototype.trim()String.prototype.trimLeft()String.prototype.trimRight()String.prototype.startsWith()
Changed functionality in JavaScript 1.8.1
- Implicit setting of properties in object and array initializers no longer execute setters in JavaScript. This makes the behavior of setting the values of properties more predictable.