How to search through nested JSON arrays in PHP - php

Question

I'm sorry if I don't use the correct terminology, I'm still learning. I'm trying to figure out how to search a JSON array that has nested arrays in it for a specific value, and then return an associated value.
My problem is similar to this answered question on StackOverflow (How to search through a JSON Array in PHP), but I want to be able to find an item by id in either people or dog or any other nested array. Essentially I want to convert people below in the foreach to a wildcard.
Here is my JSON data - http://foothillertech.com/student/webdesign/2018/2018benrud2/tinker/dataIntro2/test/data.json
foreach($json->people as $item)
{
if($item->id == "8097")
{
echo $item->content;
}
}
Any help is greatly appreciated.

Answer 1

If id is unique in the data, you can merge the inner arrays and index them by id.
$data = json_decode($json, true);
$merged = array_merge(...array_values($data));
$indexed = array_column($merged, null, 'id');
Then you can look up any of the items by id.
echo $indexed['8097']['content'] ?? 'not found';
This only works if id is unique. If not, indexing by id will result in data loss.

Answer 2

In this case, simply do two loops.
$json = json_decode('{
"people": [
{
"id": "8080",
"content": "foo"
},
{
"id": "8097",
"content": "bar"
}
],
"dogs": [
{
"id": "8081",
"content": "spot"
},
{
"id": "8091",
"content": "max"
}
]
}');
foreach($json as $key=>$value){
//$key = people or dogs
//$value = stdClass()
foreach($value as $item)
{
if($item->id == "8097")
{
echo $item->content;
}
}
}
Output
bar
Sandbox
If we used 8081 instead of 8097 I would expect to get 'spot`. And testing that, I do indeed get that (which is in dogs).