Should an array be declared before using it? [closed]

Answer 1

A is better. B will result in a PHP Notice when run, but will still work the same. As some other people mentioned and I overlooked initially, A will also make your code more robust by making sure that $array is what you want it to be when you need it and not some other variable type or previously defined variable.

Edit: the one time PHP doesn't throw a notice when using an undefined variable is when appending to an uninitialized array. From php.net:

E_NOTICE level error is issued in case of working with uninitialized variables, however not in the case of appending elements to the uninitialized array.