value = $value; } public function getValue() { return $this->value; } } //standard: pass by value //with &; pass by reference function show(&$x, &$y) { $tmp = $x; $x = $y; $y = $tmp; } $a = new Holder('a'); $b = new Holder('b'); show($a, $b); echo $a->getValue() . ", " . $b->getValue() . "
"; echo "

"; echo "The above output is generated by the code below:
"; highlight_file( __FILE__ ); ?>