Common PHP Errors and How to Fix Them
Browse all documented PHP errors with detailed explanations, root causes, and step-by-step fixes.
Trying to access array offset on value of type null in /var/www/html/data.php on
This error occurs when a developer tries to access an element of an array or object using a key or property, but the val…
PDOException: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate en
This error occurs when you attempt to insert a duplicate value into a column that has a unique constraint, such as a pri…
SQLSTATE[22007]: Invalid datetime format: 1292 Truncated incorrect datetime valu
This error occurs when the date or time format used in a MySQL query does not match the format specified in the database…
Uncaught Illuminate\Database\QueryException with message 'SQLSTATE[23000]: Integ
This error occurs when attempting to insert a new record into a database table with a unique key constraint that is alre…
Call to a member function fetchAll() on null in /var/www/html/database.php on li
This error occurs when a developer tries to call a method on a null or non-object variable, which in this case is a resu…
syntax error, unexpected 'if' (T_IF), expecting ',' or ';' on line 10
This error occurs when PHP encounters a syntax that is not allowed in the current context. In this case, the 'if' statem…
Cannot send headers. Output started at /var/www/html/index.php:123
This error occurs when PHP tries to send HTTP headers after the output has already started. In PHP, headers must be sent…
Fatal error: Uncaught Error: Cannot pass string to argument 1 of fgets(), expect
This error occurs when a PHP function that expects a resource (like a file pointer) is passed a string instead.…
The route 'login' was not defined. Please define this route in the routes/web.ph
This error occurs when Laravel's route resolver cannot find a defined route. Laravel uses a router to map URLs to specif…
Warning: Cannot redeclare class Foo in /var/www/html/autoloader.php on line 55
This error occurs when a PHP script attempts to declare a class with the same name in a different scope, usually due to …
Fatal error: Allowed memory size of 41943040 bytes exhausted (tried to allocate
This error occurs when PHP's maximum memory limit is exceeded, usually due to a large dataset or an inefficient algorith…
Cannot pass parameter 2 by reference in /var/www/html/api.php on line 56
This error occurs when trying to pass a value by reference in a function parameter that has been declared to be passed b…
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