public function isValid($target)
    {
        if ($target >= $this->start && $target <= $this->end) {
            return true;
        } else {
            $this->violate(sprintf($this->message, $this->start, $this->end));
            return false;
        }
    }
public function isValid($target)
    {
        if ($target >= $this->start && $target <= $this->end) {
            return true;
        } else {
            $this->violate(sprintf($this->message, $this->start, $this->end));
            return false;
        }
    }
public function isValid ( $ target ) { if ( $ target >= $ this -> start && $ target <= $ this -> end ) { return true ; } else { $ this -> violate ( sprintf ( $ this -> message , $ this -> start , $ this -> end ) ) ; return false ; } }
Checks whether values

@param string $target
@return boolean
Checks whether values