Answers for "javascript check if json contains object"

if json valide js

function IsJsonString(str) {
    try {
        JSON.parse(str);
    } catch (e) {
        return false;
    }
    return true;
}

if condition to whether json object has jsonarray or jsonobject

JSONObject json = new JSONObject(jsonString);

if (json.has("data")) {

    JSONObject dataObject = json.optJSONObject("data");

    if (dataObject != null) {

        //Do things with object.

    } else {

        JSONArray array = json.optJSONArray("data");

        //Do things with array
    }
} else {
    // Do nothing or throw exception if "data" is a mandatory field
}