Optimize JSonArray for Loop

Question

Today, I'm trying to optimize my JSONArray regarding android developer documentation. I was supposed to optimize it but there is error message coming out.

JSONArray infojson = json.getJSONArray("getInfo");          
for(int i=0;i < infojson.length();i++){                                     
    JSONObject e = infojson.getJSONObject(i);
    hm = new HashMap<String, Object>();
    hm.put(MYNAME, e.getString("uname"));
    hm.put(MYAGE, e.getString("uage"));
}

And I've optimized above coding as follow

JSONArray infojson = jsonObject.getJSONArray("getInfo");
for (Object o : infojson ) {
    JSONObject jsonLineItem = (JSONObject) o;
    String myname = jsonLineItem.getString("uname");
    String myage = jsonLineItem.getString("uage");
}

Unfortunately, I got the following error message occuring on "infojson ) {"

Can only iterate over an array or an instance of java.lang.Iterable

Answer 1

You can't use JSONArray with the that syntax as it doesn't implement Iterable interface. As a side note, the micro performance improvement you get probably won't affect your application performance as JSON results that are returned from the WebService are typically not large in size.

Answer 2

You're getting that error because JSONArray doesn't implement the Iterable interface.

In short, there's no clean way to solve this; you'd have to serialize the JSONObjects into your custom class.

To save you time though, using (Object one: all) over (i=0; i < all.getLength(); i++) won't give you any runtime improvements.

Just stick to the normal for loop.