tasks a-s

Task/Polymorphism/PHP/polymorphism-1.php

@@ -0,0 +1,71 @@
+class Point
+{
+  protected $_x;
+
+  protected $_y;
+
+  public function __construct()
+  {
+    switch( func_num_args() )
+    {
+      case 1:
+        $point = func_get_arg( 0 );
+        $this->setFromPoint( $point );
+        break;
+      case 2:
+        $x = func_get_arg( 0 );
+        $y = func_get_arg( 1 );
+        $this->setX( $x );
+        $this->setY( $y );
+        break;
+      default:
+        throw new InvalidArgumentException( 'expecting one (Point) argument or two (numeric x and y) arguments' );
+    }
+  }
+
+  public function setFromPoint( Point $point )
+  {
+    $this->setX( $point->getX() );
+    $this->setY( $point->getY() );
+  }
+
+  public function getX()
+  {
+    return $this->_x;
+  }
+
+  public function setX( $x )
+  {
+    if( !is_numeric( $x ) )
+    {
+      throw new InvalidArgumentException( 'expecting numeric value' );
+    }
+
+    $this->_x = (float) $x;
+  }
+
+  public function getY()
+  {
+    return $this->_y;
+  }
+
+  public function setY( $y )
+  {
+    if( !is_numeric( $y ) )
+    {
+      throw new InvalidArgumentException( 'expecting numeric value' );
+    }
+
+    $this->_y = (float) $y;
+  }
+
+  public function output()
+  {
+    echo $this->__toString();
+  }
+
+  public function __toString()
+  {
+    return 'Point [x:' . $this->_x . ',y:' . $this->_y . ']';
+  }
+}

Task/Polymorphism/PHP/polymorphism-2.php

@@ -0,0 +1,63 @@
+class Circle extends Point
+{
+  private $_radius;
+
+  public function __construct()
+  {
+    switch( func_num_args() )
+    {
+      case 1:
+        $circle = func_get_arg( 0 );
+        $this->setFromCircle( $circle );
+        break;
+      case 2:
+        $point = func_get_arg( 0 );
+        $radius = func_get_arg( 1 );
+        $this->setFromPoint( $point );
+        $this->setRadius( $radius );
+        break;
+      case 3:
+        $x = func_get_arg( 0 );
+        $y = func_get_arg( 1 );
+        $radius = func_get_arg( 2 );
+        $this->setX( $x );
+        $this->setY( $y );
+        $this->setRadius( $radius );
+        break;
+      default:
+        throw new InvalidArgumentException( 'expecting one (Circle) argument or two (Point and numeric radius) or three (numeric x, y and radius) arguments' );
+    }
+  }
+
+  public function setFromCircle( Circle $circle )
+  {
+    $this->setX( $circle->getX() );
+    $this->setY( $circle->getY() );
+    $this->setRadius( $circle->getRadius() );
+  }
+
+  public function getPoint()
+  {
+    return new Point( $this->getX(), $this->getY() );
+  }
+
+  public function getRadius()
+  {
+    return $this->_radius;
+  }
+
+  public function setRadius( $radius )
+  {
+    if( !is_numeric( $radius ) )
+    {
+      throw new InvalidArgumentException( 'expecting numeric value' );
+    }
+
+    $this->_radius = (float) $radius;
+  }
+
+  public function __toString()
+  {
+    return 'Circle [' . $this->getPoint() . ',radius:' . $this->_radius . ']';
+  }
+}

Task/Polymorphism/PHP/polymorphism-3.php

@@ -0,0 +1,12 @@
+$point = new Point( 1, 5 );
+$circle = new Circle( 1, 5, 6 );
+
+$point->output();
+// or
+echo $point;
+
+echo "\n";
+
+$circle->output();
+// or
+echo $circle;