Are private constants possible in PHP?

Question

PHP does not allow ``` class Foo { private const my_private_const; ``` but of course allows ``` const my_const; ``` So in effect constants are global because I can access `my_const` anywhere using `Foo::my_const` Is there a way to make private constants?

Accepted Answer

The answer is a simple "no". PHP doesn't support this concept. The best you can do is a `private static` variable in the class, which isn't as good of course because it's not readonly. But you just have to work around it.

Edit

Your question got me thinking - here's something I've never tried, but might work. Put another way "this is untested". But say you wanted a "private constant" called `FOO`:

```
// "Constant" definitions
private function __get($constName){
    // Null for non-defined "constants"
    $val = null;

switch($constName){
        case 'FOO':
            $val = 'MY CONSTANT UNCHANGEABLE VALUE';
            break;
        case 'BAR':
            $val = 'MY OTHER CONSTANT VALUE';
            break;
    }

return $val;
}
```

Of course your syntax would look a bit odd:

```
// Retrieve the "constant"
$foo = $this->FOO;
```

...but at least this wouldn't work:

```
$this->FOO = 'illegal!';
```

Maybe something worth trying?

Cheers

Are private constants possible in PHP?

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