PHP Fatal Error: How to Fix 'Constant Expression Contains Invalid Operations'?

PHP Error: Unraveling the Mystery of "Constant Expression Contains Invalid Operations"

Facing a frustrating "Fatal error: Constant expression contains invalid operations" error message, you've narrowed down the culprit to line 214 of your config.php file. Let's analyze the issue and find a solution.

The error stems from an improper initialization of a static property ($dbname) in line 214. The syntax:

protected static $dbname = 'mydb_'.$appdata['id'];

mistakenly attempts to initialize the static property with a dynamic value stored in $appdata['id']. However, static properties in PHP can only be initialized with literals or constants before PHP 5.6.

To resolve this error, you have two options:

1. Use a constant string: Replace $appdata['id'] with a constant string, ensuring that the value is fixed at compile time.
2. Remove the static attribute: Since static properties are resolved at compile time, remove the static attribute. This will allow you to initialize the property with a dynamic value.

Remember that static properties are instantiated at compile time, making it impossible to modify their values at runtime. This limitation safeguards memory usage and performance by preventing unexpected behavior.

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