Quick Answer

Handle null object references.

Understanding the Issue

This fatal error occurs when trying to call a method on a variable that is null, indicating the object was not properly instantiated.

The Problem

This code demonstrates the issue:

Php Error 
$user = null;
$user->getName(); // Fatal error

The Solution

Here's the corrected code:

Php Fixed 
// Solution 1: Check for null
if ($user !== null) {
    $user->getName();
}

// Solution 2: Null-safe operator (PHP 8+)
$name = $user?->getName();

// Solution 3: Provide default
$user = $potentialUser ?? new GuestUser();

// Solution 4: Exception handling
try {
    $name = $user->getName();
} catch (Error $e) {
    log_error($e);
    $name = 'Unknown';
}

// Solution 5: Type hinting
function processUser(User $user) {
    // $user guaranteed to be valid
}

Key Takeaways

Always verify object initialization before method calls.