php read content from json file and then update - php

Question

I have the following data from an api call:
$userId = 1234; and $accessToken = 6789;. I want to write this to a json file called users.json.
Following this I make another api call and receive the following data:
$userId = 5678; and $accessToken = 0123;.
I then want to add this to the json file so that it looks like this:
[
{
"userId": "1234",
"accessToken": "6789"
},
{
"userId": "5678",
"accessToken": "0123"
},
]
My code for writing to the json file looks like this. The $userId and $accessToken are defined elsewhere and are returning the correct values:
$content = file_get_contents('users.json');
$tempArray = json_decode($content, true);
print_r($tempArray); // this doesn;t show anything as the users.json file contains `null`
array_push($tempArray, $userId);
array_push($tempArray, $accessToken);
$jsonData = json_encode($tempArray);
file_put_contents('users.json', $jsonData);
Unfortunately this isn't working. When I view the json file it just contains null Can anyone see any error with my code?
Thanks Raul

Answer 1

Your code is wrong. Correct it to look like this
<?php
$content = file_get_contents('users.json');
$tempArray = json_decode($content, true);
if(empty($tempArray)){
$tempArray = [];
}
$newData = [
"userId" => $userId,
"accessToken" => $accessToken
];
array_push($tempArray, $newData);
$jsonData = json_encode($tempArray);
file_put_contents('users.json', $jsonData);
This will definitely work.

Answer 2

You need to to json_decode($content, true); to obtain an array and not an object.
See http://php.net/manual/fr/function.json-decode.php
Also the array_push is not correctly called.
It should be : array_push($tempArray, ["userid"=>$userId,"accesstoken" => $accessToken]);

Answer 3

You have error in json file so that all suggesion not working remove , at end of array. Then try below code :
Your json file should be:
[
{
"userId": "1234",
"accessToken": "6789"
},
{
"userId": "5678",
"accessToken": "0123"
}
]
php :
$content = file_get_contents('user.json');
$tempArray = json_decode($content,true);
$new_array = array("userId"=>$userId,"accesstoken"=>$accessToken);
array_push($tempArray, $new_array);
$jsonData = json_encode($tempArray);
file_put_contents('user.json', $jsonData);