overloading and overriding in php

1class Shape {
2   const Pi = 3.142 ;  // constant value
3  function __call($functionname, $argument){
4    if($functionname == 'area')
5    switch(count($argument)){
6        case 0 : return 0 ;
7        case 1 : return self::Pi * $argument[0] ; // 3.14 * 5
8        case 2 : return $argument[0] * $argument[1];  // 5 * 10
9    }
10
11  }
12
13 }
14 $circle = new Shape();`enter code here`
15 echo "Area of circle:".$circle->area()."</br>"; // display the area of circle Output 0
16 echo "Area of circle:".$circle->area(5)."</br>"; // display the area of circle
17 $rect = new Shape();
18 echo "Area of rectangle:".$rect->area(5,10); // display area of rectangle
19

1<?php
2
3class Foo {
4   function myFoo() {
5      return "Foo";
6   }
7}
8
9class Bar extends Foo {
10   function myFoo() {
11      return "Bar";
12   }
13}
14
15$foo = new Foo;
16$bar = new Bar;
17echo($foo->myFoo()); //"Foo"
18echo($bar->myFoo()); //"Bar"
19?>
20