PHP json_encode encoding numbers as strings

Note that since PHP 5.3.3, there's a flag for auto-converting numbers (the options parameter was added in PHP 5.3.0):

$arr = array( 'row_id' => '1', 'name' => 'George' );
echo json_encode( $arr, JSON_NUMERIC_CHECK ); // {"row_id":1,"name":"George"}

try $arr = array('var1' => 100, 'var2' => 200);
$json = json_encode( $arr, JSON_NUMERIC_CHECK);

But it just work on PHP 5.3.3. Look at this PHP json_encode change log http://php.net/manual/en/function.json-encode.php#refsect1-function.json-encode-changelog

I've done a very quick test :

$a = array(
    'id' => 152,
    'another' => 'test',
    'ananother' => 456,
);
$json = json_encode($a);
echo $json;

This seems to be like what you describe, if I'm not mistaken ?

And I'm getting as output :

{"id":152,"another":"test","ananother":456}

So, in this case, the integers have not been converted to string.

Still, this might be dependant of the version of PHP we are using : there have been a couple of json_encode related bugs corrected, depending on the version of PHP...

This test has been made with PHP 5.2.6 ; I'm getting the same thing with PHP 5.2.9 and 5.3.0 ; I don't have another 5.2.x version to test with, though :-(

Which version of PHP are you using ? Or is your test-case more complex than the example you posted ?

Maybe one bug report on http://bugs.php.net/ could be related ? For instance, Bug #40503 : json_encode integer conversion is inconsistent with PHP ?

Maybe Bug #38680 could interest you too, btw ?

I, likewise was reading from a DB (PostgreSQL) and everything was a string. We loop over each row and do things with it to build up our final results array, so I used

$result_arr[] = array($db_row['name'], (int)$db_row['count']);

within the loop to force it to be an integer value. When I do json_encode($result_arr) now, it correctly formats it as a number. This allows you to control what is and is not a number coming from your database.

EDIT:

The json_encode() function also has the ability to do this on the fly using the JSON_NUMERIC_CHECK flag as a second argument to it. You need to be careful using it though as shown in this users example in the documentation (copied below): http://uk3.php.net/manual/en/function.json-encode.php#106641

<?php
// International phone number
json_encode(array('phone_number' => '+33123456789'), JSON_NUMERIC_CHECK);
?>

And then you get this JSON:

{"phone_number":33123456789}