PHP Academy · Lesson

PHP Error Types and Reporting

Understand notices, warnings, and fatal errors plus error_reporting levels.

PHP Error Types and Reporting is a free PHP Academy lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the PHP Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.

PHP Error Types

PHP has several severity levels of errors:

Notice — minor issue, execution continues
Warning — non-fatal issue, execution continues
Fatal Error — execution stops immediately
Parse Error — syntax error, stops before execution
Deprecated — feature will be removed

error_reporting()

Control which errors PHP reports with error_reporting():

<?php
// Show all errors (development)
error_reporting(E_ALL);

// Hide notices and deprecated
error_reporting(E_ALL & ~E_NOTICE & ~E_DEPRECATED);

// Production: no display, log to file
error_reporting(E_ALL);
ini_set('display_errors', '0');
ini_set('log_errors', '1');
ini_set('error_log', '/var/log/php_errors.log');

display_errors vs log_errors

Key php.ini settings for error handling:

display_errors = On — show errors in browser (dev only)
display_errors = Off — hide from users (production)
log_errors = On — write to error_log file
error_log = /path/to/file — specify log location

Never display errors to users in production!

Triggering Errors with trigger_error

Generate your own PHP errors with trigger_error():

<?php
function divide(int $a, int $b): float {
    if ($b === 0) {
        trigger_error('Division by zero', E_USER_WARNING);
        return 0.0;
    }
    return $a / $b;
}

echo divide(10, 0);  // triggers E_USER_WARNING

Custom Error Handler

<?php
set_error_handler(function(int $errno, string $errstr, string $file, int $line): bool {
    $message = "[$errno] $errstr in $file:$line";
    error_log($message);
    if ($errno === E_USER_ERROR) {
        http_response_code(500);
        die('Internal error — please try again later');
    }
    return true;  // don't execute PHP internal error handler
});

trigger_error('Custom error message', E_USER_ERROR);

Common Error Sources

Typical causes of PHP errors:

Accessing undefined array key → Notice
Calling a function that returns false, then using the result → Warning
Calling an undefined function → Fatal Error
Missing semicolon → Parse Error
Division by zero → Warning (returns INF or NAN)

Error Suppression Operator @

The @ operator suppresses errors from a single expression — avoid it, use proper error handling:

<?php
// Bad: hides errors silently
$result = @file_get_contents('missing.txt');

// Good: check explicitly
$result = file_get_contents('missing.txt');
if ($result === false) {
    // handle the error
    echo 'File not found';
}

PHP 8 JIT and Error Changes

PHP 8 made some error handling stricter:

Many warnings promoted to TypeError/ValueError
str_contains/starts_with/ends_with replacing regex for simple checks
Passing wrong argument types throws TypeError by default

ini_set at Runtime

Override php.ini settings at runtime:

<?php
// Display errors during development
if (getenv('APP_ENV') === 'development') {
    ini_set('display_errors', '1');
    ini_set('display_startup_errors', '1');
    error_reporting(E_ALL);
} else {
    ini_set('display_errors', '0');
    ini_set('log_errors', '1');
    error_reporting(E_ALL);
}

Checking Error Level

Detect error levels with bitwise AND:

<?php
$level = error_reporting();

if ($level & E_NOTICE) {
    echo 'Notices are reported';
}
if ($level & E_WARNING) {
    echo 'Warnings are reported';
}

// Check specific error types
echo (E_ALL & E_NOTICE) ? 'E_ALL includes E_NOTICE' : 'no';

Error Logging Best Practices

Good error logging habits:

Always log errors in production
Include context: user ID, request URL, timestamp
Use structured logging (JSON) for easier parsing
Rotate log files to prevent disk fill
Monitor logs with tools like ELK, Datadog, or Papertrail

Quick Check

Which PHP error type stops execution immediately?

Recap: PHP Error Reporting

Error handling essentials:

Error types: Notice, Warning, Fatal, Parse, Deprecated
Set level with error_reporting()
Display off + log on in production
Register custom handler with set_error_handler()
Never suppress with @ in production code

Frequently asked questions

Is the “PHP Error Types and Reporting” lesson free?

Yes — the full text of “PHP Error Types and Reporting” is free to read here on the web, and the PHP Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the PHP Academy course, upgrade to CoddyKit PRO.

What will I learn in “PHP Error Types and Reporting”?

Understand notices, warnings, and fatal errors plus error_reporting levels. You practise PHP Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start PHP Academy?

No prior experience is required. PHP Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.

How long does the “PHP Error Types and Reporting” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

Can I write and run code in this PHP Academy lesson?

Yes. Every PHP Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.

All lessons in this course

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