Accessing a member of a "variable" class

Question

A variable named $class contains the name of a class.

How can I access a static member of that class?

I need an approach that would work in PHP 5.2.

The following works in PHP 5.3:

$class::$default_error_message;

In PHP 5.2 it outputs:

unexpected T_PAAMAYIM_NEKUDOTAYIM

Btw, T_PAAMAYIM_NEKUDOTAYIM?! PHP doesn't cease to amaze me.

FYI: "PAAMAYIM NEKUDOTAYIM" is apparently Hebrew for "double colon". PHP also defines the parser token `T_DOUBLE_COLON`, as an alias I guess, but the Hebrew version is a well known joke by now. — AgentConundrum, Apr 13 '11 at 20:59

score 2 · Answer 1 · edited Apr 13 '11 at 21:26

2

Use get_class_vars

$values = get_class_vars($class);

echo $values["default_error_message"];

CodePad Demo

edited Apr 13 '11 at 21:26

Emanuil Rusev

34,563
55
137
201

answered Apr 13 '11 at 20:58

Mike Lewis

63,433
20
141
111

He's trying to read a static variable, not call a function. – Frank Farmer Apr 13 '11 at 20:59
Very true, changed up the answer. – Mike Lewis Apr 13 '11 at 21:01
I believe `$default_error_message` must be become `"default_error_message"`. Other then that, that's a great approach. Quite elegant. – Emanuil Rusev Apr 13 '11 at 21:06
That's correct, sorry about that. – Mike Lewis Apr 13 '11 at 21:07
the docs make it sound like `get_class_vars` returns the default values of each variable, which isn't necessarily the same as the current value. See the example, in which $var2 and $var3 are assigned values in the constructor which are not reflected in the output of the function. – Frank Farmer Apr 13 '11 at 23:16

score 1 · Accepted Answer · answered Apr 13 '11 at 20:56

function getStaticMember($class, $member) {
    if(is_object($class))
        $class = get_class($class);
    $classObj = new ReflectionClass($class);
    $result = null;
    foreach($classObj->getStaticProperties() as $prop => $value) {
        if($prop == $member) {
            $result = $value;
            break;
        }
    }
    return $result;
}

Also:

In PHP, the scope resolution operator is also called Paamayim Nekudotayim (Hebrew: פעמיים נקודתיים‎), which means "twice colon" or "double colon" in Hebrew.

Accessing a member of a "variable" class

2 Answers2