//Check if a JSON string is valid:
$isValid = simdjson_is_valid($jsonString); //return bool

//Parsing a JSON string. similar to the json_decode() function but without the fourth argument
$parsedJSON = simdjson_decode($jsonString, true, 512); //return array|object|null. "null" string is not a standard json

/*
{
  "Image": {
    "Width":  800,
    "Height": 600,
    "Title":  "View from 15th Floor",
    "Thumbnail": {
      "Url":    "http://www.example.com/image/481989943",
      "Height": 125,
      "Width":  100
    },
    "Animated" : false,
    "IDs": [116, 943, 234, 38793, {"p": "30"}]
  }
}
*/

//note. "/" is a separator. Can be used as the "key" of the object and the "index" of the array
//E.g. "Image/Thumbnail/Url" is ok.


//get the value of a "key" in a json string
$value = simdjson_key_value($jsonString, "Image/Thumbnail/Url");
var_dump($value); // string(38) "http://www.example.com/image/481989943"

$value = simdjson_key_value($jsonString, "Image/IDs/4", true);
var_dump($value); 
/*
array(1) {
  ["p"]=>
  string(2) "30"
}
*/

//check if the key exists. return true|false|null. "true" exists, "false" does not exist, "null" string is not a standard json
$res = simdjson_key_exists($jsonString, "Image/IDs/1");
var_dump($res) //bool(true)

// count the values
$res = simdjson_key_count($jsonString, "Image/IDs");
var_dump($res) //int(5)