Class constants

[cs.punk]

<?php

class constantTest {

const HELLOWORLD = 'maybe not';

function __construct()
{
	echo HELLOWORLD; // Output: HELLOWORLD
	echo constant('HELLOWORLD'); // Output: Warning: constant() [function.constant]: Couldn't find constant HELLOWORLD
	echo  self::HELLOWORLD . "\n"; // Output: maybe not
}
}

$bob = new constantTest();

 

I have read through the manual but as far as I can see all three methods should output the constant rather than just the last one.

Question: Why?

[Buddski]

I believe it is because the first 2 examples you attempted are looking in the global scope for the constant.

 

Like superglobals, the scope of a constant is global. You can access constants anywhere in your script without regard to scope. For more information on scope, read the manual section on variable scope.

 

So to reference the HELLOWORLD constant inside your class you should call self:: as your third example shows.

[requinix]

As the manual page says, constant will work with class constants as long as you prefix the class name.

echo constant(__CLASS__ . "::HELLOWORLD");