PHP（新）对象的数组

Question

I'm currently developing a web-based administration frontend, for an application I developed, in PHP (after several failed attempts to get Lua working with Apache and Nginx being a little weird, too) and PHP's arrays are frustrating me.

I'm trying to initialize an array of objects as I would in any other OOP-capable language:

private $leftNavItems = array(
        new LeftNavItem("./img/icon/status.png", "status", "App Status", "./articles/app_status.phtml", "app_status")
    );

however, I'm getting an error stating "expression not allowed as field default value".

Why can I not initialize an array with new objects? Would I have to work around this by using temporary variables and array_push?

EDIT : I'm coming from OOP languages such as C#, Java and C++, as well as pure procedural languages such as Lua.

Answer 1

Move the initialization part in the class' constructor __construct() . Object properties can be initialized on their definition only with values that can be evaluated during compilation.

class X {
    private $leftNavItems = array();

    public function __construct()
    {
        $this->leftNavItems = array(
            new LeftNavItem("./img/icon/status.png", "status", "App Status", "./articles/app_status.phtml", "app_status")
        );
    }
}

The initializers of the properties are evaluated during the compilation; they are not pieces of code to be executed when the class is initialized.

Your code attempts to initialize the variable by creating a object. Creating new objects is an activity that happens during the code execution.