Am 18.02.20 um 12:20 schrieb Nikita Popov:
> Hi internals,
>
> https://github.com/php/php-src/pull/5172 changes var_dump() to use
> serialize_precision instead of precision to dump floating-point numbers.
>
> To recap: serialize_precision defaults to -1, which will print exactly as
> many floating-point digits as are needed to represent the number
> accurately. precision defaults to 14, which will print a shorter but
> potentially inaccurate float representation.
>
> The motivation here is that var_dump() is debugging functionality and
> should print values as accurately as possible. The single most common bug
> report we receive is some kind of variation on:
>
> $sum = 0.1 + 0.2;
> var_dump($sum); // float(0.3)
> var_dump($sum == 0.3); // bool(false) WTF???
>
> After this change, this would instead be:
>
> $sum = 0.1 + 0.2;
> var_dump($sum); // float(0.30004)
> var_dump($sum == 0.3); // bool(false) Makes sense...
>
> I have little hope that developers will suddenly start understanding
> floating-point numbers, but at least this should reduce the amount of
> confusion.
>
> Does anyone see an issue with doing this change?
You mean apart from people now filing bugs how var_dump() can output
such a nonsensical number from such an easy equation? And that it again
shows that PHP is not a real programming language (unlike JavaScript)
and should never be used at all?
Nope ;-)
Cheers
Andreas
PS: I'd absolutely appreciate the change!!!
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