PHP class for circle: Area and circumference calculation

PHP OOP: Exercise-2 with Solution

Write a PHP class called 'Circle' that has a radius property. Implement methods to calculate the circle's area and circumference.

Sample Solution:

PHP Code :

<?php
class Circle {
    private $radius;

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

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

    public function getCircumference() {
        return 2 * pi() * $this->radius;
    }
}

$circle = new Circle(7);
echo "Area: " . $circle->getArea() . "</br>";
echo "Circumference: " . $circle->getCircumference() . "</br>";
?>

Sample Output:

Area: 153.9380400259
Circumference: 43.982297150257

Explanation:

In the above exercise -

• The "Circle" class has one private property: $radius, which represents the circle radius.
• The constructor method __construct() initializes the circle radius.
• The getArea() method calculates and returns the area of the circle using the formula: π * r^2, where π is a constant value obtained from the pi() function, and r is the radius of the circle.
• The getCircumference() method calculates and returns the circle circumference using the formula: 2*π*r.

Flowchart:

PHP Code Editor:

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