- json_decode: documentation ( source)
- print_r: documentation ( source)
- preg_replace: documentation ( source)
<?php
$x = json_decode('{
"key": "levels",
"value": "[{role_id:1, access_level_id:3}, {role_id:2, access_level_id:1}, {role_id:3, access_level_id:2}]",
"description": ""
}', true);
$x['value'] = json_decode(preg_replace('/(\w+)(?=:)/', '"$1"', $x['value']), true);
print_r($x);