# Feature Compatibility

As GJS' underlying JavaScript engine, SpiderMonkeyopen in new window, has been upgraded and new GNOME stack integrations have been improved, various features have been both deprecated and added. This chart is a working guide of what features are usable on different versions of GJS

Alpha/Early1.44.x-1.46.x1.48.x1.50.x1.52.x
SpiderMonkey Version?24385252
Classes
Lang.Interface✔️✔️⚠️⚠️
Lang.Class✔️✔️✔️⚠️⚠️
ES6 Classes✔️✔️
Strings
String.prototype.containsopen in new window✔️✔️✔️
String.prototype.includesopen in new window✔️✔️
String.prototype.padStartopen in new window✔️✔️
String.prototype.padEndopen in new window✔️✔️
String Templatesopen in new window✔️✔️✔️
Objects
Object.values()open in new window✔️✔️
Arrays
Array.prototype.includes()open in new window✔️✔️
Last Updated: 10/24/2021, 8:20:27 AM