These are tasks that deal with error handling and logging. They allow you to define your own bug management rules, and change the way errors can creep in. This allows you to modify and upgrade an error report to suit your needs.

Syntax

error_function(error_level,error_message, error_file,error_line,error_context);


Example

define your own bug management rules 

<?php
   error_reporting( E_ERROR );
   
   function handleError($errno, $errstr,$error_file,$error_line) {
      echo "Error: [$errno] $errstr - $error_file:$error_line";
      echo "Terminating PHP Script";
      die();
   }
   
   //set error handler
   set_error_handler("handleError");
   
   //trigger error
   myFunction();
?>

Predefined 

These error reporting levels are the various types of error a user-defined handle can be used for. These cabinet values ​​are grouped by using operator

The constants below are always available as part of the PHP core.

Value Constant Description
1 E_ERROR (int) Fatal run-time errors. These indicate errors that can not be recovered from, such as a memory allocation problem. Execution of the script is halted.
2 E_WARNING (int) Run-time warnings (non-fatal errors). Execution of the script is not halted.
4 E_PARSE (int) Compile-time parse errors. Parse errors should only be generated by the parser.
8 E_NOTICE (int) Run-time notices. Indicate that the script encountered something that could indicate an error, but could also happen in the normal course of running a script.
16 E_CORE_ERROR (int) Fatal errors that occur during PHP's initial startup. This is like an E_ERROR, except it is generated by the core of PHP.
32 E_CORE_WARNING (int) Warnings (non-fatal errors) that occur during PHP's initial startup. This is like an E_WARNING, except it is generated by the core of PHP.
64 E_COMPILE_ERROR (int) Fatal compile-time errors. This is like an E_ERROR, except it is generated by the Zend Scripting Engine.
128 E_COMPILE_WARNING (int) Compile-time warnings (non-fatal errors). This is like an E_WARNING, except it is generated by the Zend Scripting Engine.
256 E_USER_ERROR (int) User-generated error message. This is like an E_ERROR, except it is generated in PHP code by using the PHP function trigger_error().
512 E_USER_WARNING (int) User-generated warning message. This is like an E_WARNING, except it is generated in PHP code by using the PHP function trigger_error().
1024 E_USER_NOTICE (int) User-generated notice message. This is like an E_NOTICE, except it is generated in PHP code by using the PHP function trigger_error().
2048 E_STRICT (int) Enable to have PHP suggest changes to your code which will ensure the best interoperability and forward compatibility of your code.
4096 E_RECOVERABLE_ERROR (int) Catchable fatal error. It indicates that a probably dangerous error occurred, but did not leave the Engine in an unstable state. If the error is not caught by a user defined handle (see also set_error_handler()), the application aborts as it was an E_ERROR.
8192 E_DEPRECATED (int) Run-time notices. Enable this to receive warnings about code that will not work in future versions.
16384 E_USER_DEPRECATED (int) User-generated warning message. This is like an E_DEPRECATED, except it is generated in PHP code by using the PHP function trigger_error().
32767 E_ALL (int) All errors and warnings, as supported, except of level E_STRICT prior to PHP 5.4.0.

Using die() function

When writing your PHP program you should check the entire error state before proceeding to take appropriate action where necessary.

<?php
   if(!file_exists("/tmp/test.txt")) {
      die("File not found");
   }else {
      $file = fopen("/tmp/test.txt","r");
      print "Opend file sucessfully";
   }
   // Test of the code here.
?>