This is example code of php inheritance parents and child. extend is the keyword to inherit from the parent class.
<?php abstract class Shape { protected $color; public function __construct($color = 'blue') { $this->color = $color; } public function getColor() { return $this->color; } abstract protected function getArea(); } class Square extends Shape { protected $length = 4; public function getArea() { return pow($this->length, 2); } } class Triangle extends Shape { protected $base = 4; protected $height = 7; public function getArea() { return .5 * $this->base * $this->height; } } class Circle extends Shape { protected $radius = 5; public function getArea() { return M_PI * pow($this->radius, 2); } } // long hand methods // $circle = new Circle; // echo $circle->getArea(); //shorthand echo (new Circle)->getArea();