Fatal error Constant expression contains invalid operations

Question

I am getting an error:

Fatal error: Constant expression contains invalid operations in config.php on line 214

That line was:

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

Whether I did any mistakes in quotes? Or somewhere else?

My search for the error message only showed a different source cause (a dynamic default value in a function definition).

Answer 1

Hello @kartik,

This is because a static variable contains a constant value in it. But in your case:

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

$appdata['id'] is dynamic that can change its value during the execution. That's why the error is showing.

Hope it helps!!