Define a class with a constructor

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class A {
    public $attribute1;
    public function operation1() {
	echo "operation1:".$this->attribute1."
";
    }
}

class B extends A {
    public $attribute2;
    public function operation2() {
	echo "Operation2
";
	$this->attribute1=$this->attribute2;
    }
}

$b = new B();
$b->attribute1=27;
$b->operation1();
$b->attribute2 = 10;
$b->operation2();
$b->operation1();

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