100 > 100 gives true

Asked Oct 07 '21 at 14:30

Active Oct 07 '21 at 14:31

Viewed 79 times

I have this object:

{
    timestamp:2021-09-10T08:30:00Z,
    keys:[
        {usage_point_id:24329232979894,key:69},
        {usage_point_id:24327496366232,key:7.4},
        {usage_point_id:30002431659877,key:0},
        {usage_point_id:24348769886471,key:1.3755},
        {usage_point_id:24328075237474,key:10.4},
        {usage_point_id:24348480450805,key:11.8245}
    ]
}

I want to make sure that the sum of all those percent is not superior to 100. So, I do:

$measuresByTS->each(function ($measures) {
    if ($measures['keys']->sum('key') > 100) {
        dump("sum is superior to 100 : ". $measures['keys']->sum('key'));
    }
});

Weird thing is in my case, I manually checked the sum and it is equal to 100, not superior. In this case, in my code, it will display:

"sum is superior to 100 : 100"

I tried to cast $measures['keys']->sum('key') to float, but it is not working.

Anybody knows why this is happening ?

Using Laravel 8 / PHP 8

edited Oct 07 '21 at 14:31

DarkBee

16,592
6
46
58

asked Oct 07 '21 at 14:30

Juliatzin

18,455
40
166
325

2

`ini_set('precision', 15); echo (69 + 7.4 + 0 + 1.3755 + 10.4 + 11.8245);` results in `100.000000000000014210854715202` – ceejayoz Oct 07 '21 at 14:34
2

Like ceejayoz said, this is a rounding problem, use round() to get the correct result. – Wimanicesir Oct 07 '21 at 14:35
1

https://www.php.net/manual/en/book.bc.php ... – Martin Zeitler Oct 07 '21 at 14:35
@ceejayoz I thought this woudl be it too but I cannot get that result or anything other than `100` ?? Locally or on eval https://3v4l.org/AbMmh – RiggsFolly Oct 07 '21 at 14:44
1

There's even 13 digits until the offset becomes obvious. – Martin Zeitler Oct 07 '21 at 14:46
Thanks, I rounded to 8 decimals my result and it worked like a charm ! – Juliatzin Oct 07 '21 at 14:46
@RiggsFolly I did it in Laravel's tinker, PHP 8. https://i.stack.imgur.com/joXLO.png Max precision can vary from system to system, IIRC. – ceejayoz Oct 07 '21 at 14:52
@RiggsFolly You apparently need at least [17 digits](https://3v4l.org/14hiX). – Álvaro González Oct 07 '21 at 17:36
@ÁlvaroGonzález Ah, thanks for that – RiggsFolly Oct 08 '21 at 14:23

100 > 100 gives true

0 Answers0