Reference Error

What This Error Means

This error occurs when a variable has not been declared or initialized before it's being used in a script.

Why It Happens

This error typically happens when a developer forgets to declare a variable or a function before using it. In this case, the variable `$database_connection` is being used without being declared or initialized.

How to Fix It

1. 1To fix this error, you need to declare the variable before using it. You can do this by assigning a value to the variable using the assignment operator (=). For example:
2. 2// Before (broken code)
3. 3$result = queryDatabase($database_connection);
4. 4// After (fixed code)
5. 5$database_connection = new mysqli('localhost', 'username', 'password', 'database');
6. 6$result = queryDatabase($database_connection);

Example Code Solution

$database_connection = new mysqli('localhost', 'username', 'password', 'database');
$result = queryDatabase($database_connection);

$database_connection = new mysqli('localhost', 'username', 'password', 'database');
$result = queryDatabase($database_connection);