Use of #file, #line, #function when debugging

Uplift iOS Interview

The Guide is for YOU if
  • You are preparing for an iOS interview and want to improve your skills and knowledge and looking to level up your interview game and land your dream job.
  • You want to gain confidence and ease during iOS interviews by learning expert tips and curated strategies.
  • You want access to a comprehensive list of iOS interview QA to practice and prepare.

#file, #line and #function are very common to debug features that are available in other languages like C++. I found it very useful to implement debug/logging manager. We can get the current file name, line number and function name from the #file, #line and #function respectively.

func debugPrint(_ info: Any) {
    // You can also use if debug to print output only in debug environment
    // #if DEBUG
    // Your print statement
    // #endif

    print("📂 \(#file) L[\(#line)] - \(#function) - \(info)")

func test() {
    debugPrint("Test function executed!")


// Output
// 📂 Debug.playground L[9] - debugPrint(_:) - Test function executed!
// 📂 Debug.playground L[9] - debugPrint(_:) - 10

✍️ Written by Ishtiak Ahmed

👉 Follow me on XLinkedIn

Get Ready to Shine: Mastering the iOS Interview

Enjoying the articles? Get the inside scoop by subscribing to my newsletter.

Get access to exclusive iOS development tips, tricks, and insights when you subscribe to my newsletter. You'll also receive links to new articles, app development ideas, and an interview preparation mini book.

If you know someone who would benefit from reading this article, please share it with them.