iOS Mobile Application Developer Interview Questions and Answers

To efficiently fetch and display 1000 images in a grid with error handling, consider batching API calls, implementing pagination, and using placeholders for missing images.

• Batch API calls in smaller groups to prevent overwhelming the server and network.

• Implement pagination to fetch images in chunks, reducing the load on the server and improving performance.

• Use placeholders for missing images to maintain the grid layout and user experience.

• Handle API call failures gracefully b...read more

Security provisions can be provided through encryption, authentication, authorization, and secure coding practices.

• Implement end-to-end encryption to protect data in transit and at rest.

• Use secure authentication methods like OAuth, JWT, or biometrics.

• Implement role-based access control for authorization.

• Regularly update and patch the application to fix security vulnerabilities.

• Follow secure coding practices to prevent common security issues like SQL injection, XSS, and CSRF.

• U...read more

To decode optional in Swift, use optional binding or optional chaining.

• Use optional binding with if let or guard let to safely unwrap an optional and assign it to a new variable.

• Use optional chaining with a question mark (?) to access properties, methods, and subscripts of an optional that might currently be nil.

The DEFER method is used in Swift to delay the execution of a block of code until the current scope is exited.

• DEFER is used to ensure cleanup or finalization code is executed, regardless of how the current scope is exited.

• It is commonly used to release resources, close files, or perform other cleanup tasks.

• DEFER blocks are executed in reverse order of their declaration.