instantiate a class from a variable in PHP?

Question

I know this question sounds rather vague so I will make it more clear with an example:

$var = 'bar';
$bar = new {$var}Class('var for __construct()'); //$bar = new barClass('var for __construct()');

This is what I want to do. How would you do it? I could off course use eval() like this:

$var = 'bar';
eval('$bar = new '.$var.'Class(\'var for __construct()\');');

But I'd rather stay away from eval(). Is there any way to do this without eval()?

Answer 1

Put the classname into a variable first:

$classname=$var.'Class';

$bar=new $classname("xyz");

This is often the sort of thing you'll see wrapped up in a Factory pattern - there's an example in the PHP manual.

Answer 2

class Test {

public function yo() {
 return 'yoes';
}
}

$var = 'Test';

$obj = new $var();
echo $obj->yo(); //yoes