array_merge(): Argument #1 is not an array - php

Question

need your help on this... got an error on my array_merge
here's my code:
//first
$url1="https://www.zopim.com/api/v2/chats";
$ch1 = curl_init();
curl_setopt($ch1, CURLOPT_URL, $url1);
curl_setopt($ch1, CURLOPT_USERPWD, "$username:$password");
curl_setopt($ch1, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
curl_setopt($ch1, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch1, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($ch1, CURLOPT_RETURNTRANSFER, true);
$output1 = curl_exec($ch1);
$info1 = curl_getinfo($ch1);
curl_close($ch1);
$chats1 = json_decode($output1,true);
//second
$url2="https://www.zopim.com/api/v2/chats?page=2";
$ch2 = curl_init();
curl_setopt($ch2, CURLOPT_URL, $url2);
curl_setopt($ch2, CURLOPT_USERPWD, "$username:$password");
curl_setopt($ch2, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
curl_setopt($ch2, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch2, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($ch2, CURLOPT_RETURNTRANSFER, true);
$output2 = curl_exec($ch2);
$info2 = curl_getinfo($ch2);
curl_close($ch2);
$chats2 = json_decode($output2,true);
$r = [];
if(is_array($chats1) && is_array($chats2))
{
foreach($chats1 as $key => $array)
{
$r[$key] = array_merge($chats2[$key], $array);
}
}
else
{
echo 'problem with json';
}
echo json_encode($r, JSON_UNESCAPED_SLASHES);
I need to combine a two json using array_merge()... im using curl authorization to call my API..
but when i try to run the code it has a error:
here's number 44 error:

Answer 1

This means your json_decode fails. It will fail if the string is no valid JSON. When it fails json_decode returns either null or false, so you have to check if the response is valid:
$chats1 = json_decode($output1, true);
$chats2 = json_decode($output2, true);
if ($chats1 && $chats2 && is_array($chats1) && is_array($chats2)) {
// your code goes here
}