Check if a particular JSON Object is available or not in php

Question

I have following JSON:

$p={
  "main1" : [
    {
      "child1" : valueA,
      "child2" : valueB,
      "child3" : valueC,
    },
    {
      "child1" : value1,
      "child3" : value3,
    },
  ],
  "main2" : "valueMain2"
}

The element child2 has to be checked if it exists or not and then the value is taken. I am using json_decode:

$response = json_decode($p,true);

How do I check if an element exists or not in PHP? Do I have to make separate function or is there built-in functionality?

Answer 1

The same way you'd check if a key of any array exists:

with isset($array['key']) or array_key_exists('key',$array).

Answer 2

Here's how I've been doing it.

$child2exists = count($response['main1']['child2']);

If ($child2exists == 1) 
{ 
    echo "EXISTS"; 
}
else
{ 
    echo "DOESNT EXIST"; 
}

Hope this helps.