I already know what is IOC and also I have done some PHP projects with Laravel (4.3) framework which is IOC based. also I know ZEND (1.12) and have done some projects with it. I know how ZEND MVC system works. I know what are ZEND plugins (front controller plugin , resource plugin , action helper , view helper ). I also know how ZEND 1 bootstrapping system works and I know the request lifecycle.
and I know that ZEND 1 doesn't use IOC container. I want to know that . is there any problem with ZEND 1 that doesn't use IOC container ?? I mean , Is zend 1 good enough though it doesnt use IOC?? in other words what kind of problems with old php frameworks have been soled with new PHP frameworks using IOC??? in what conditions and what projects I should IOC base PHP frameworks?? and if it's necessary to use a IOC based PHP framework can I add an IOC component to zend 1 ??? I want to know in depth. sorry for bad English.