The print function

Sprinkling print() functions all over the code for debugging might sound primitive, but it has been the preferred technique for many programmers.

Typically, the print() functions are added before the line where the exception has occurred. It can be used to print the state of variables in various lines leading to the exception. You can trace the execution path by printing something when a certain line is reached.

In development, the print output usually appears in the console window where the test server is running. Whereas in production, these print outputs might end up in your server log file where they would add a runtime overhead.

In any case, it is not a good debugging technique to use in production. Even if you do, the print functions that are added for debugging should be removed from being committed to your source control.