There is a big difference between the two in that you can reference project resources in your XML layouts. They are available in the application context and are therefore accessible across the global application. The biggest advantages of using project resources is the ease of access and that they allow you to organize your project … Read more
Lets start with a bit of background: What happens when you start an application? The OS starts a process and assigns it a unique process id and allocates a process table.A process start an instance of DVM(Dalvik VM); Each application runs inside a DVM. A DVM manages class loading unloading, instance lifecycle, GC etc. Lifetime … Read more
Your methods are missing the static keyword. Change function getInstanceByName($name=””){ to public static function getInstanceByName($name=””){ if you want to call them statically. Note that static methods (and Singletons) are death to testability. Also note that you are doing way too much work in the constructor, especially all that querying shouldn’t be in there. All your … Read more
I’m guessing you’ve done something like: class Foo { static void Bar(); }; … static void Foo::Bar() { … } The “static void Foo::Bar” is incorrect. You don’t need the second “static“.
In the context of a class, static variables are on the class scope (not the object) scope, but unlike a const, their values can be changed. class ClassName { static $my_var = 10; /* defaults to public unless otherwise specified */ const MY_CONST = 5; } echo ClassName::$my_var; // returns 10 echo ClassName::MY_CONST; // returns … Read more
PHP can’t parse non-trivial expressions in initializers. I prefer to work around this by adding code right after definition of the class: class Foo { static $bar; } Foo::$bar = array(…); or class Foo { private static $bar; static function init() { self::$bar = array(…); } } Foo::init(); PHP 5.6 can handle some expressions now. … Read more
Add to your cpp file: constexpr char foo::baz[]; Reason: You have to provide the definition of the static member as well as the declaration. The declaration and the initializer go inside the class definition, but the member definition has to be separate.
The class declaration should be in the header file (Or in the source file if not shared). File: foo.h class foo { private: static int i; }; But the initialization should be in source file. File: foo.cpp int foo::i = 0; If the initialization is in the header file then each file that includes the … Read more