IF Conditions statement not working in my controller

I am new to Codeigniter. For some reasons if statement is not evaluating properly within my controller.
I will appreciate any help. See my code snipet below

public function states(){
$this->load->view('sap/header');

$state = str_replace ("%20", " ", $this->uri->segment(3, 0));
$lga =  str_replace ("%20", " ", $this->uri->segment(4, 0));
$pms = str_replace ("%20", " ", $this->uri->segment(5, 0)); //plazas markets and shops


$data['state'] = $state;
$data['lga'] = $lga;
$data['pms'] = $pms;
//$data['plaza'] = $plaza;

$id = $this->welcome_model->getStateID($state);
$stateid = $id[0]['state_id'];



//$lgaid = $lgaid[0]['lga_id'];

if(!($plaza === 0)){

}
//
elseif(!($lga=== 0)){

}
else (!($pms === 0)){

}

$this->load->view('sap/footer');
}

It is because you use comparison with strong typing. If the parameters are expected to be numbers, cast them to integer type.

Further to ivantcholakov's suggestion, insert the following in the first line of your public function states() {

error_reporting(-1); ini_set('display_errors', 'true');

Both errors and warnings should show and you can change the script.

Also str_replace(...); always and only returns a string or error.

In general with PHP, only use === if you understand why you are using it, and you have a specific reason (for example you really need to know that something is boolean false rather than just an empty string which evaluates to false), in most cases == is the operator you are looking for.

Php === is strict and evaluates variable types as well as the value. An empty string does not have a zero integer value...