On 04/09/2023 05:35, tyamahori wrote:
Dear PHP users.
I have questions about the behavior `null + null = 0`.
Since PHP4.3.0, `null + null` becomes `0`.
https://3v4l.org/YX3Od#veol
Form php-src,
https://github.com/php/php-src/blob/e2189e5f376092eeaeb4c06ff9b5918bfc016917/Zend/zend_operators.c#L325
It seems _zendi_try_convert_scalar_to_number converts null to 0.
Do you know who decided this behavior ?
Do you know how did this behavior come about?
Regards.
Kazuki
What you're looking at here is type coercian, or as PHP refers to it,
type juggling.
You're using a non-numerica type as a number when you use the +
operator. This has the effect of casting null first to an int, which
results in your calculation becoming 0 + 0.
More details on PHPs type juggling can be found at
https://www.php.net/manual/en/language.types.type-juggling.php
Thanks,
Ash
--
www.ashleysheridan.co.uk
