Concatenation while instantiating a class

I'd like to instantiate a model (in Zend Framework) using a generic way. I have $type variable which contains the name of the model. I'd like to write something like this

$db = new Admin_Model_{$type}();

But it doesn't work, Is there any way to 开发者_C百科accomplish this?

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You need to have the entire class name as a string in order for this to work:

$model = 'Admin_Model_' . $type;
$db = new $model();