How do I access static member of a class?

KoolKabin picture KoolKabin · Sep 29, 2010 · Viewed 83.8k times · Source

I am trying to access static member of a class.

my class is:

class A
{
    public static $strName = 'A is my name'
    public function xyz()
    {
        ..
    }
    ..
}
//Since I have bunch of classes stored in an array
$x = array('A');
echo $x::$strName;

I am getting error while printing. How can I print 'A is my name'

Answer

Anthony Forloney picture Anthony Forloney · Sep 29, 2010

If A is a class, you can access it directly via A::$strName.

class A {
    public static $strName = 'A is my name';
}

echo A::$strName; // outputs "A is my name"

Update:

Depending on what you have inside your array, whether its what I like to define as class objects or class literals could be a factor. I distinguish these two terms by,

$objClasses = array(new A(), new B()); // class objects
$myClasses = array('A','B');           // class literals

If you go the class literals approach, then using a foreach loop with PHP5.2.8 I am given a syntax error when using the scope resolution operator.

foreach ($myClasses as $class) {
     echo $class::$strName;
  //syntax error, unexpected '::', expecting ',' or ';'
}

So then I thought about using the class objects approach, but the only way I could actually output the static variable was with an instance of an object and using the self keyword like so,

class A {
    public static $strName = 'A is my name';

    function getStatic() {
        return self::$strName;
    }
}

class B {
    public static $strName = 'B is my name';

    function getStatic() {
        return self::$strName;
    }
}

And then invoke that method when iterating,

foreach($objClasses as $obj) {
    echo $obj->getStatic();
}

Which at that point why declare the variable static at all? It defeats the whole idea of accessing a variable without the need to instantiate an object.

In short, once we have more information as to what you would like to do, we can then go on and provide better answers.