Question

How to define and use abstract class in PHP

Answer 1

abstract class AbstractClass
{
    // Force extending class to define this method
    abstract protected function getValue();

    // Common method
    public function printValue() {
        echo $this->getValue() . "<br />";
    }
}

class Class1_From_AbstractClass extends AbstractClass
{
    protected function getValue() {
        return "Class1_From_AbstractClass";
    }
}

class Class2_From_AbstractClass extends AbstractClass
{
    public function getValue() {
        return "Class2_From_AbstractClass";
    }
}

$class1 = new Class1_From_AbstractClass;
$class1->printValue();


$class2 = new Class2_From_AbstractClass;
$class2->printValue();

 
/*
run: 

Class1_From_AbstractClass
Class2_From_AbstractClass

*/

 

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