math/Vector.php
public function length() : float
    {
        static $result;

        return null !== $result ? $result : $result = sqrt($this->lengthSquared());
    }
public function length() : float
    {
        static $result;

        return null !== $result ? $result : $result = sqrt($this->lengthSquared());
    }
public function length ( ) : float { static $ result ; return null !== $ result ? $ result : $ result = sqrt ( $ this -> lengthSquared ( ) ) ; }
Returns the length of the Vector.

@return  float
Returns the length of the Vector .