Problem Statement
How does GetX handle reactive state management? Explain Rx observables and GetX/Obx widgets.
Explanation
GetX uses reactive programming with observable variables created using .obs extension on values, like var count = 0.obs creates an RxInt. Accessing the value requires .value property, and assigning to .value automatically notifies listeners. Any GetX or Obx widget observing that variable automatically rebuilds when the value changes, without manual listener registration.
Controllers extend GetxController containing business logic and observable state. Create controller with Get.put(CounterController()) for dependency injection, then access anywhere with Get.find<CounterController>(). Controllers have lifecycle methods like onInit, onReady, and onClose for initialization and cleanup. GetX automatically disposes controllers when they're no longer needed if using Get.lazyPut.
Use Obx(() => Text('${controller.count.value}')) for minimal reactive rebuilds - only the Obx widget rebuilds when observables it accesses change. GetX<CounterController>((controller) => ...) is similar but provides the controller to the builder. Use GetBuilder for manual updates calling update() in controller - useful when you don't want full reactivity or need more control over rebuilds.
GetX's reactivity is automatic and simple but less explicit than other solutions. The .obs and .value syntax is convenient but not obvious to newcomers. Some developers love the minimal code and productivity, others prefer explicit patterns. GetX works well for rapid development and smaller apps where convenience matters more than architectural purity. Consider team preference and project scale when choosing GetX.