json_encode($array) reverse order of my php array - php

Question

I have json_encode($array) it gives me a list in a different order on google chrome

Answer 1

array_reverse: used to Return an array with elements in reverse order, e.g:
$array = array_reverse($array);
echo json_encode($array,JSON_UNESCAPED_UNICODE);

Answer 2

The encoding is done on the backend by the PHP so Google Chrome has nothing to do with this issue.
Check your array order before you encode it.

Answer 3

check the value in $array using var_dump to make sure, thats the order you want.
Edit: look at the 3rd example in the manual

Answer 4

What does your JSON data look like? If:
{1,2,3}
Your browser will not necessarily preserve the order. But if formatted as a JSON array:
[1,2,3]
Then the order will be preserved.

Answer 5

If your array is associative, but indexed by integers (like $arr1 = ['3' => 'x', '2' => 'a', '1' => 'b'];), the browser (when parsing JSON) assumes that the keys of the array indicate the order in which the values are stored (as in a classical, non-associative array - like $arr2 = ['x','a','b'];).
See for yourself - compare the results of parsing the JSON generated from those two associative arrays - one is indexed by non-integer strings (A), the other one is indexed by integers (even if they are string-typed in PHP) (B).
For both examples the values in PHP are stored in order: 'x', 'a', 'b', and only the keys are different.
A) associative array, indexed by strings
<?php
$arr1 = [
'foo' => 'x',
'bar' => 'a',
'baz' => 'b'
];
$json = json_encode($arr1); // $json is now a string: '{"foo":"x","bar":"a","baz":"b"}'
And then, in the browser:
var jsonData = JSON.parse('{"foo":"x","bar":"a","baz":"b"}');
console.log(jsonData);
// prints {foo: "x", bar: "a", baz: "b"} - the keys are in different order then expected!
B) associative array, indexed by integers (even if they are strings in PHP!)
<?php
$arr1 = [
'3' => 'x',
'2' => 'a',
'1' => 'b'
];
$json = json_encode($arr1); // $json is now a string: '"{"3":"x","2":"a","1":"b"}"'
And then, in the browser:
var jsonData = JSON.parse('"{"3":"x","2":"a","1":"b"}"');
console.log(jsonData);
// prints {1: "b", 2: "a", 3: "x"} - the keys are in different order then expected!
As you see - the JSON parser assumes a classical array when the
indices are integers.
So if you need to maintain the order, I'd suggest switching to a classical array and perhaps adding an order / key field to the JSON (for sorting purposes - if you need it):
$arr1 = [
'3' => 'x',
'2' => 'a',
'1' => 'b'
];
$json = json_encode(array_values($arr1)); // note the array_values() here - but this way you loose the index keys
Another way:
$arr1 = [
'3' => [ 'key' => '3', 'value' => 'x'],
'2' => [ 'key' => '2', 'value' => 'a'],
'1' => [ 'key' => '1', 'value' => 'b'],
];
$json = json_encode(array_values($arr1));
// this way you have both values and keys,
// and the parsed JSON will be in the exact order you want it to be