Re: Make var_dump() use serialize_precision

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(0.30000000000000004) > 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!!! -- ,,, (o o) +---------------------------------------------------------ooO-(_)-Ooo-+ | Andreas Heigl | | mailto:andreas@heigl.org N 50°22'59.5" E 08°23'58" | | http://andreas.heigl.org http://hei.gl/wiFKy7 | +---------------------------------------------------------------------+ | http://hei.gl/root-ca | +---------------------------------------------------------------------+

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