OO PHP contruct variables wrong

Question

Doing some OO PHP. I'm getting undefined variables on line 11 and 31 and I'm not sure why.

<?php 

    class geometricObject {
        private $color;

        public function __construct($color){
            $this->color = $color;
        }

        public function getColor(){
            return $color;
        }

        public function setColor($color){
            $this->color = $color;
        }
    }

    class circle extends geometricObject {
        private $radius;

        public function __construct($radius, $color){
            parent::__construct($color);
            $this->radius = $radius;
        }

        public function getRadius(){
            return $radius;
        }

        public function getArea(){
            return (pi() * pow($radius, 2));
        }

        public function getSurfaceArea(){
            return (2 * pi() * $radius);
        }

        public function setRadius($radius){
            $this->radius = $radius;
        }
    }

?>

<?php 

    include_once 'templates/classes.php';

    $myCircle = new circle(10, "green");

    $circleArea = $myCircle->getArea();

    $color = $myCircle->getColor();

    include_once 'output.php';

?>

<html>
<body>

<?php echo $circleArea; echo $color; ?>

</body>
</html>

Yes, but it should have been *in the question*. We shouldn't have to follow links to code when it's perfectly easy to include code in the original post. (You could have posted a *shorter* example, too.) — Jon Skeet, Dec 22 '12 at 13:33
Possible duplicate of [PHP: “Notice: Undefined variable” and “Notice: Undefined index”](http://stackoverflow.com/q/4261133/367456) — hakre, Dec 22 '12 at 13:47

score 2 · Answer 1 · answered Dec 22 '12 at 13:31

2

You forgot $this->

return $this->color;

answered Dec 22 '12 at 13:31

Codler

10,951
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score 2 · Accepted Answer · answered Dec 22 '12 at 13:31

2

You're getting the error because $color is undefined within the method scope. You only pass the $color argument to the constructor and the setColor method.

To access it in other class methods you would use $this->color not $color

answered Dec 22 '12 at 13:31

David Barker

14,484
3
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Thank you all. Also learned an important terminology. Method scope. – user1683645 Dec 22 '12 at 13:37

score 1 · Answer 3 · answered Dec 22 '12 at 13:33

1

You have forgot $this before that variables you should do it this way: return $this->color;

answered Dec 22 '12 at 13:33

Mustafa Shujaie

806
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OO PHP contruct variables wrong

3 Answers3