Hi Yasuo On Mon, Jul 27, 2015 at 11:17 PM, Yasuo Ohgaki <yohg...@ohgaki.net> wrote:
> > Get JSON data from Google maps and store the data using PHP, then > users lose last 2 digits of fraction part by default. The value is changed > and wrong. This is definitely a bug. > > I don't really get why you use Google maps as an example. Do you actually know what's the difference between two distances that differs after rounding with precision 14? I just tried it on http://www.ig.utexas.edu/outreach/googleearth/latlong.html and set Lat 1: 51.602097123457 ; Long 1: -0.120667 Lat 2: 51.602097123458 ; Long 2: -0.120667 The difference is 1.114e-10 km which is 0.0001114 millimetres. Are you actually serious about that? :) > We can write > > $old = ini_set('precision', 17); > json_encode($var); > ini_set('precision', $old); > You can set it once in your ini file if you need such precision. > > everywhere to workaround this problem. > > Question is "Is this the way it should be?". > > I have already said that using precision ini wasn't the best idea. However json_encode is not the same as serialize and we should not ever change its output in a bug fixing release. Doing that could cause also other issues as this is a BC break. Lets imagine that someone set low precision on purpose just to limit precision and save some space when transferring data . If you change it, then it's screwed up because it will use different ini. We don't know what people do in their code and we should not break it. As I said this is not a bug but we could consider changing that if the RFC proposing such change passes. Cheers Jakub
