$json = '{"a":1,"b":2,"c":3}';
var_dump(json_decode($json)); //converts json to array
$array = [ "a" => 1, "b" => 2, "c" => 3];
echo json_encode($json_encode($json)); //converts array to json
$json = '{"courseList":[
{"course":"1", "course_data1":"Computer Systems(Networks)"},
{"course":"2", "course_data2":"Audio and Music Technology"},
{"course":"3", "course_data3":"MBA Digital Marketing"}
]}';
var_dump(json_decode($json));