PHP-用json_decode浮点数错误的精度

Question

I have an issue when trying to decode JSON with the json_decode function in PHP 7.0.21. I am able to replicate this problem with these lines of code:

Code:

<?php
$inputJSON = '{"value":0.00000883}';
$outputJSON = json_decode($inputJSON);
print_r($outputJSON);

Output:

stdClass Object
(
    [value] => 8.83E-6
)

I also tried changing the precision with ini_set('precision', 8); which doesn't change the output.

The only fixes I found online were regex replaces which changed the number into a string but that's a hack and a good solution. I don't want to change ALL my float numbers to strings.

Why is this happening and how can I fix this properly without adding a lot of overhead like using number_format . Is the parsing simply broken in json_decode?

Answer 1

You can use number_format to remove the e-6 so you can store correctly in your database;

<?php

$inputJSON = '{"value":0.00000883}';
$outputJSON = json_decode($inputJSON);

$formatted = number_format($outputJSON->value,8);

print_r($formatted);

outputs: 0.00000883

Although, I'm pretty sure MySQL should handle 8.83E-6 as an input.