Strategy Pattern

The strategy pattern use different ways to deal with different things:

<?php /** * a simple strategy pattern */class strategy{function __construct(){}/** * if a and b are string will call stradd function * if a and b are number will call numadd function * @param $a * @param $b * @return mix */function add($a,$b){if (is_string($a) && is_string($b)){return $this->stradd($a,$b);}else if (is_numeric($a) && is_numeric($b)){return $this->numadd($a,$b);}else{return null;}}private function stradd($a,$b){return $a.$b;}private function numadd($a,$b){return $a+$b;}}$strategy = new strategy();$str1 = 'stringone';$str2 = 'stringtwo';echo $strategy->add($str1,$str2);echo ' ';$num1 = 23;$num2 = 43;echo $strategy->add($num1,$num2);