Angular Interview Practice

What is change detection in Angular?

1. A method to hide components conditionally

2. Angular's mechanism to track changes in data and update the DOM

3. A way to optimize performance by preventing updates

4. Angular's way of logging application errors

The correct answer is: Angular's mechanism to track changes in data and update the DOM

Change detection in Angular refers to the framework's mechanism that tracks changes in the application's data model and subsequently updates the Document Object Model (DOM) to reflect those changes. This responsive system ensures that the user interface is always in sync with the underlying data state. When a component's state changes, Angular uses change detection to determine which parts of the UI need to be updated, allowing for efficient rendering and providing a smooth user experience. There are various strategies for change detection in Angular, including Default and OnPush, which help developers optimize the performance of their applications by selectively checking for changes in data. The other options do not accurately describe change detection: while hiding components conditionally relates to visibility logic, optimizing performance through preventing updates and logging errors do not capture the essence of how Angular manages data changes and reflects them in the user interface.