How can one systematically troubleshoot PHP code to isolate and address specific issues, such as empty page displays or unexpected results?

Issue: To troubleshoot PHP code and isolate specific issues like empty page displays or unexpected results, one can use debugging techniques such as printing variables, checking error logs, and using tools like xdebug to step through code execution. Example PHP code snippet for printing variables to debug:

// Example variable to debug
$example_var = "Hello World";

// Print variable to check its value
echo $example_var;