PHP function call in class property

Question

Why can\'t I do this in PHP? Where Database is a singleton class and getInstance() returns a PDO object.

Answer 1

You can't execute code to produce the value of a static variable as, by definition, static variables are affected at compile time, see :

• http://en.wikipedia.org/wiki/Static_memory_allocation
• http://en.wikipedia.org/wiki/Static_variable

Getting the run-time value of a variable, or calling a function (run-time too) can't be done at compile-time to they cannot be affected to static variables.