Angular Interview Practice

What occurs during the update phase of the Angular execution cycle?

1. Angular refreshes the browser completely

2. Angular applies detected changes to the DOM

3. Angular compiles templates at runtime

4. Angular navigates to a different route

The correct answer is: Angular applies detected changes to the DOM

During the update phase of the Angular execution cycle, Angular applies detected changes to the DOM. This phase is essential because it ensures that the view accurately reflects the model’s current state after any changes or updates have been detected during the change detection process. Angular’s change detection mechanism monitors the component’s data-bound properties and observes any changes that occur, whether through user interactions, asynchronous operations, or updates triggered by other components. Once changes are detected, Angular updates the corresponding parts of the DOM to match these changes, thereby keeping the user interface synchronized with the underlying data model. This process involves efficiently updating only the elements that need to be refreshed instead of re-rendering the entire component, which optimizes performance and enhances user experience. In contrast, refreshing the browser would not typically happen during the update phase, as this would lead to a full reload of the application rather than a targeted update of the view. Similarly, compiling templates at runtime refers to the initial rendering phase rather than updates to existing views. Navigation to a different route involves routing logic, which is separate from the update process, focusing more on changing views rather than applying changes to the existing DOM.