What are the common mistakes developers make with defer in Go?

What are the common mistakes developers make with defer in Go?

One common mistake is assuming that deferred functions execute immediately when called. They actually run after the surrounding function returns.

Can you give an example of that?

Sure! If you have a function that opens a file and defers the closing, the file won't close until the function exits, which could lead to resource leaks.

Are there any performance issues related to using defer?

Yes, using defer can introduce a slight overhead because it adds a function call to the stack. In performance-critical code, this might be a concern.

What about using defer in loops?

That's another common mistake! Deferring a function inside a loop can lead to unexpected behavior, as all deferred calls will execute after the loop finishes.