Как преобразовать json в массив php

<?php

$json = '{ "keywords": [ "hexlet", "sicp", "project" ] }';


var_dump(json_decode($json, true));
//=> array(1) {
//=>   ["keywords"]=>
//=>   array(3) {
//=>     [0]=>
//=>     string(6) "hexlet"
//=>     [1]=>
//=>     string(4) "sicp"
//=>     [2]=>
//=>     string(7) "project"
//=>   }
//=> }