Why Fragments, and when to use Fragments instead of Activities?

Here is a detailed answer to your Android interview question about Fragments:

Why Fragments?

Fragments were introduced in Android 3.0 (Honeycomb) to provide a modular approach to building Android user interfaces. Fragments allow you to encapsulate a portion of the UI and its behavior into reusable, self-contained components. This provides several key benefits:

• Modularity: Fragments make it easier to build flexible, dynamic user interfaces by allowing you to combine multiple Fragments within a single Activity.
• Reusability: Fragments can be reused across multiple Activities, promoting code reuse and consistency.
• Adaptability: Fragments can adapt their behavior and layout based on the available screen size, allowing your app to provide an optimal experience on different devices and screen sizes.
• Lifecycle management: Fragments have their own lifecycle callbacks, making it easier to manage the state and behavior of the UI components within them.

When to use Fragments instead of Activities

Here are some common scenarios where using Fragments is preferred over using Activities:

1. Multi-pane layouts: When building tablet-optimized layouts with multiple panes of content, Fragments allow you to easily manage and combine these panes within a single Activity.

2. Master-detail flows: For apps that display a list of items (master) and a detailed view of the selected item (det...