CURLOPT_POSTFIELDS format - php

Question

I am trying to pass a json string into a curlopt_postfield.
curl_setopt($ch, CURLOPT_POSTFIELDS, $postfields);
I have a working hard coded example. However I am having trouble making it dynamic.
$test = "84560";
$data = "{\"id\":\"" .$test. "\"}";
$data2 = "{\"id\":\"84560\"}";
curl_setopt($ch, CURLOPT_POSTFIELDS, $data2);
Why does $data2 work and $data fail?
I have tried json encoding, utf8 encoding, and lots of variations of escaping the quotes all to no avail. What am I missing? I do not get an error simply a NULL response.
Here is the full code. Still not able to get it working. Any additional suggestions as I have tried everything I have found.
$test = "84560";
$data = "{\"id\":\"" .$test. "\"}";
$data2 = "{\"id\":\"84560\"}";
$result2 = getJson("results.json?", $data2);
function getJson($endpoint, $postfields)
{
$URL = "https://app.mobilecause.com/api/v2/reports/". $endpoint;
$ch = curl_init();
$headers = [];
$headers[] = "Authorization: Token token=\"[token goes here]\"";
$headers[] = "Accept: application/json";
$headers[] = "Content-Type: application/json";
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
curl_setopt($ch, CURLOPT_URL, $URL);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $postfields);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "GET");
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
$result = curl_exec($ch);
if (curl_errno($ch))
{
echo 'Error:' . curl_error($ch);
}
curl_close ($ch);;
return $result;
}

Answer 1

You should simply try:
<?php
$data = array('id' => 84560);
$json = json_encode($data);
echo $json; // Will print { id: 84560 }