<?php class Circle { const pi = 3.14; public function Area($radius) { return self::pi * ($radius * $radius); } } $get = new Circle(); echo $get->Area(5);
<?php class Circle { const pi = 3.14159; public function Area($radius) { return self::pi * $radius ** 2; } } //echo Circle::pi; $circle = new Circle(); echo $circle->Area(100);