json_encode Change My Array Into stdClass Object, Is This Normal? - php

Question

I have this code :
<?php
$array = array ( array ('pcs'=>'23', 'kg'=>'3'),
array ('pcs'=>'24', 'kg'=>'4'),
array ('pcs'=>'25', 'kg'=>'5'));
echo '<pre>';
print_r($array);
$array = json_encode($array);
echo $array;
$array = json_decode($array);
echo '<pre>';
print_r($array);
?>
and here's the output :
Array
(
[0] => Array
(
[pcs] => 23
[kg] => 3
)
[1] => Array
(
[pcs] => 24
[kg] => 4
)
[2] => Array
(
[pcs] => 25
[kg] => 5
)
)
[{"pcs":"23","kg":"3"},{"pcs":"24","kg":"4"},{"pcs":"25","kg":"5"}]
Array
(
[0] => stdClass Object
(
[pcs] => 23
[kg] => 3
)
[1] => stdClass Object
(
[pcs] => 24
[kg] => 4
)
[2] => stdClass Object
(
[pcs] => 25
[kg] => 5
)
)
why my array becomes stdClass Object? can I still manipulates stdClass Object just like an array?
UPDATE : I got this error when I tried to echo-ing $array[0]['pcs'] :
Fatal error: Cannot use object of type stdClass as array in /home/*** on line **

Answer 1

The "problem" has nothing in common with json_encode, but rather with json_decode.
This will return an array:
$array = json_decode($array, true);

Answer 2

From the PHP Manual:
json_decode() is use to Decodes a JSON string:
When you use second param as TRUE in json_decode():
Returned objects will be converted into associative arrays.
Solution for you:
$array = json_decode($array,TRUE); // use second param as TRUE in your code.
Some Basic Examples for Understanding:
Example 1:
<?php
$json = '{"test":"test","test2":"test2"}'; // json string
echo "<pre>";
print_r(json_decode($json)); // without using second param
?>
Result (return as object):
stdClass Object
(
[test] => test
[test2] => test2
)
Example 2:
<?php
$json = '{"test":"test","test2":"test2"}';
echo "<pre>";
print_r(json_decode($json,TRUE)); // with second param true
?>
Result:
Array
(
[test] => test
[test2] => test2
)

Answer 3

That's standard php behavior. json_decode() will convert incoming data to an array of objects of class stdClass.
You can still access all elements but you have to do it more OOP:
echo $array[0]->pcs;
echo $array[0]->kg;
If you want json_decode() to reproduce your initial array use second option of the function:
$array = json_decode($array, true);
echo $array[0]['pcs'];
echo $array[0]['kg'];

Answer 4

Is this Normal?
Yes, because json_decode basically returns an object and since you didn't specify the second parameter it should return an object and not an array.
According to docs
When TRUE, returned objects will be converted into associative arrays.
so to make it return an array, is to make the second parameter equal to true.
$array = json_decode($array,true);