PHP - Constants and variables

[jjones]

In PHP you can create variable variables. Is there any way to do something similar with constants?

I'm using some variable variables like this:

$a = 'cat';

$b = 'a';

$c = $$b; (which is the same as $c = 'cat'😉

I want to do the same type of thing with a constant, where I've got the name of the constant as a string attached to a variable, and then want to use that variable to call the constant.

Any way to do this?

 

[imported_LoKe]

Not sure if I understand what you're saying, but this is what I think you're asking:

define("constant", "hey");
$var = constant;
echo constant; //outputs hey
echo $var; //outputs hey

 

[jjones]

Yep, that's what I'm talking about, but when you echo the variable, it won't output the constant value.

Actually, that's not quite what I'm doing. What you do works as it should. What I'm doing is like this:

define('_CONSTANT','hey');

$a = 'CONSTANT';

$b = '_'.$a;

echo $b;

That will output the string '_CONSTANT', not the constant value 'hey'. I want it to output that value.

 

[imported_LoKe]

EDIT: Oh, I see what's going on. Sorry, don't think I can help. Maybe you can find out more about it here.

 

[troytime]

nevermind, doesn't work for me
lemme see what i can find

 

[troytime]

seems like none of the dynamic variable techniques work for constants

might wanna mess around with eval, maybe something will work
good luck

 

[Templeton]

function constant does what you want

 

[jjones]

Well, this was so simple I feel stupid.

define('_CONSTANT','hey');

$a = STANT;

$b = '_CON'.$a;

echo constant($b); - outputs 'hey'