I think your solution by changing precision is not good enough because float summation is still not working properly.
<?php
var_dump(0.1 + 0.7);
returns:
0.7999999999
expected: 0.8
07.01.2019, 20:24, "Thomas Bley" mails@thomasbley.de:
Hello,
good point, having:
echo ini_get('precision') . PHP_EOL;
echo ini_get('serialize_precision') . PHP_EOL;
echo json_encode(array('price' => round('45.99', 2))) . PHP_EOL;
echo (0.1+0.7), json_encode(0.1+0.7) . PHP_EOL;gives (https://3v4l.org/ldgo8):
Output for 7.1.0 - 7.3.0
14
-1
{"price":45.99}
0.80.7999999999999999Output for 5.3.6 - 5.6.38, 7.0.0 - 7.0.33
14
17
{"price":45.99}
0.80.8what is the preferred way to upgrade from php 5.6 to 7.x in order to get the same results?
Regards
ThomasForce 'serialize_precision': https://3v4l.org/coaWm
But remember - a float is not suitable for output. You need rounded and formatted manually.P.S. Try with JS:
JSON.stringify(0.1+0.7);-- Semen V. Dubina https://sam002.net/
07.01.2019, 22:17, "Legale.legale" legale.legale@gmail.com:
I think your solution by changing precision is not good enough because float summation is still not working properly.<?php
var_dump(0.1 + 0.7);returns:
0.7999999999
expected: 0.8
Hi!
If you are about the proposal, then '0.1 + 0.7 !== 0.8'.
Why you expected 0.8?
Check, plz: https://3v4l.org/Ughn2
-- Semen V. Dubina https://sam002.net/
I think your solution by changing precision is not good enough because
float summation is still not working properly.<?php
var_dump(0.1 + 0.7);returns:
0.7999999999
expected: 0.8
As you may know, most computers use binary numbers. This applies to
floating-point values as well. They have a limited number of binary
digits. Many base-10 numbers cannot be expressed exactly in base-2 with
limited number of digits. When you write 0.1 + 0.7, what you get (with
double-precision floats) is closer to 0.1000000000000000055511 +
0.6999999999999999555911 = 0.7999999999999999333866. This is expected
and proper and well known.
You have to use formatting functions like number_format if you need
neatly rounded base-10 output.
There are also a lot of libraries for precise base-10 calculations. They
will be a lot slower than native binary floating-point calculations,
though.
Regards,
Lauri Kenttä