How-to articles, tricks, and solutions about UNDEFINED

file upload php $_FILES undefined index error

The error "Undefined index: (name of the file input)" in PHP usually occurs when the form that is used to upload the file is not properly configured.

How to handle Undefined Offset in laravel?

In Laravel, an "Undefined offset" error typically occurs when trying to access an array index that does not exist.

The Difference Between Null and Undefined in JavaScript

Read this JavaScript tutorial and get relevant information about the differences between null and undefined data types. Find out their similarities as well.

What does the PHP error message "Notice: Use of undefined constant" mean?

The PHP error "Notice: Use of undefined constant" means that you are trying to use a constant that has not been defined yet.