The php.ini will look like this:

; - display_errors = Off           [Security]
;     With this directive set to off, errors that occur during the execution of
;     scripts will no longer be displayed as a part of the script output, and thus,
;     will no longer be exposed to remote users.  With some errors, the error message
;     content may expose information about your script, web server, or database
;     server that may be exploitable for hacking.  Production sites should have this
;     directive set to off.
Print out errors (as a part of the output).  For production web sites,
; you're strongly encouraged to turn this feature off, and use error logging
; instead (see below).  Keeping display_errors enabled on a production web site
; may reveal security information to end users, such as file paths on your Web
; server, your database schema or other information.
display_errors = On

During apps development, u will need to display the errors in order for u to debug the code easily, so u can track what’s the error was.

Add below code on top of your PHP code:

ini_set('display_errors', 1);
ini_set('log_errors', 1);
ini_set('error_log', dirname(__FILE__) . '/error_log.txt');  // this is optional
error_reporting(E_ALL);

Happy coding with PHP.