Implementing a complete change detection mechanism for a JavaScript framework is a complex task that cannot be fully covered. However we can provide you with a simplified example that demonstrates the basic concepts involved in change detection. Let's create a simple change detection mechanism using JavaScript :

// Create a ChangeDetector class
class ChangeDetector {
  constructor() {
    this.components = new Set(); // Set to store registered components

  // Register a component for change detection
  register(component) {

  // Detect changes in registered components
  detectChanges() {
    for (const component of this.components) {
      // Assume that each component has a `hasChanges` method to check for changes
      if (component.hasChanges()) {
        component.update(); // Trigger the component's update method

// Example component
class MyComponent {
  constructor() { = {
      value: 0,

  // Method to check for changes in the component's data
  hasChanges() {
    // Compare the current value with the previous value
    return !== this.previousValue;

  // Method to update the component
  update() {
    console.log('Component updated:',;
    this.previousValue =; // Update the previous value

// Usage example
const changeDetector = new ChangeDetector();
const component = new MyComponent();

changeDetector.register(component); = 10;

changeDetector.detectChanges(); // Output: "Component updated: 10"

In this example, we create a `ChangeDetector` class responsible for managing the change detection process. The `register` method adds components to the set of registered components. The `detectChanges` method iterates over the registered components and checks for changes by calling the `hasChanges` method on each component. If changes are detected, the `update` method is triggered. We then create a sample `MyComponent` class with a `hasChanges` method that compares the current value with the previous value of the component's data. If a change is detected, the `update` method is called to log a message and update the previous value. Finally, we instantiate a `ChangeDetector` and a `MyComponent` instance. We register the component with the change detector and update the component's data value. When we call `detectChanges`, it triggers the change detection process, which detects the change in the component's data and calls the `update` method. Please note that this is a simplified example, and building a comprehensive change detection mechanism involves considering various aspects such as optimizations, handling complex data structures, supporting two-way data binding, and more. Analyzing existing JavaScript frameworks' implementations, like Angular or React, can provide additional insights into building a robust change detection system. Conclusion : It's important to understand that creating a full-fledged JavaScript framework requires a deep understanding of JavaScript, web development, and software engineering practices. It's recommended to conduct further research, study existing frameworks, and experiment with different concepts to build a reliable and performant change detection mechanism.