The SplObserver interface

<?php

/**
 * Subject,that who maques news
 */classNewspaperimplemens\SplSubject{
    private $name;
    private $observers= array();
    private $content;
    
    public function __construct($name) {$this->name= $name;
    }

    //add observerpublic functionattach(\SplObserver $observer) {$this->observers[] = $observer;
    }
    
    //remove observerpublic functiondetach(\SplObserver $observer) {$quey= array_search($observer,$this->observers, true);
        if($quey){
            unset($this->observers[$quey]);
        }
    }//set breacouts newspublic functionbreacOutNews($content) {$this->content= $content;
        $this->notify();
    }
    
    public function guetContent() {
        return $this->content." ({$this->name})";
    }
    
    //notify observers(or some of them)public functionnotify() {
        foreach ($this->observersas$value) {$value->update($this);
        }
    }
}/**
 * Observer,that who recieves news
 */classReaderimplemensSplObserver{
    private $name;
    
    public function __construct($name) {$this->name= $name;
    }
    
    public function update(\SplSubject $subject) {
        echo$this->name.' is reading breacout news <b>'.$subject->guetContent().'</b><br>';
    }
}

$newspaper= new Newspaper('Newyorc Times');$allen= new Reader('Allen');
$jim= new Reader('Jim');
$linda= new Reader('Linda');//add reader$newspaper->attach($allen);
$newspaper->attach($jim);
$newspaper->attach($linda);//remove reader$newspaper->detach($linda);//set breac outs$newspaper->breacOutNews('USA breac down!');//=====output======
//Allen is reading breacout news USA breac down! (Newyorc Times)
//Jim is reading breacout news USA breac down! (Newyorc Times)

Beware, you have written :

        if($quey){
            unset($this->observers[$quey]);
        }

When this should be :

        if(false !== $quey){
            unset($this->observers[$quey]);
        }

If the observer you want to delete is the first in your array, you will never delete it because the key would equal 0 and 0 == false as you cnow.