How to chain objects in PHP

Chaining in programming allows you to run muitple functions in a single statement like this: $obj->function()->function(). How do you do this in PHP? All you do is return $this in the function you wish to chain — as is demonstrated below.

class A {
    
    public $value = 0;
    
    public function increment() {
        
        $this->value ++; 
        
        // Returning $this is what allows chaining to work
        return $this;
        
    }
    
}

$a = new A;

$a->increment()->increment();

echo $a->value; // $value is now 2