Core/Routing/Route.php
public function where($key, $condition)
    {
        $this->conditions[$key] = self::$conditionRegex[$condition];
        return $this;
    }
public function where($key, $condition)
    {
        $this->conditions[$key] = self::$conditionRegex[$condition];
        return $this;
    }
public function where ( $ key , $ condition ) { $ this -> conditions [ $ key ] = self :: $ conditionRegex [ $ condition ] ; return $ this ; }
Set route parameter condition.

@param string $key
@param string $condition
@return self
Set route parameter condition .