Online PHP editor | output for cB3Ld

<?php //You must validate your input to make sure the string you pass is not empty and is, in fact, a string. An empty string is not valid JSON. function is_json($string) { return !empty($string) && is_string($string) && is_array(json_decode($string, true)) && json_last_error() == 0; } //I think in PHP it's more important to determine if the JSON object even has data, because to use the data you will need to call json_encode() //or json_decode(). I suggest denying empty JSON objects so you aren't unnecessarily running encodes and decodes on empty data. function has_json_data($string) { $array = json_decode($string, true); return !empty($string) && is_string($string) && is_array($array) && !empty($array) && json_last_error() == 0; } function isJson($string, $assoc = false) { var_dump(json_decode($string)); json_decode($string, $assoc); if(!empty($string) && is_string($string)) { json_decode($string, $assoc); return (json_last_error() == JSON_ERROR_NONE); // return json_decode($str) != null; } return false; } $a=['arraiii'=>['dentro'=>234]]; $b=json_encode($a); $c='{ "book": [ { "id":"01", "language": "Java", "edition": "third", "author": "Herbert Schildt" }, { "id":"07", "language": "C++", "edition": "second" "author": "E.Balagurusamy" }] }'; var_dump(isJson($b));