Converting a String to int. Set the int to 0 if String is null

Question

I have a function which saves Android data in sqlite but I have to convert the String data to an Integer.

Whenever the String is null i would like to save as 0

The following is my code which fails whenever the value is null

 int block_id = Integer.parseInt(jsonarray.getJSONObject(i).getString("block_id")); 

The block_id above is converted to an Integer.

This is what i have decided to do but still it fails to convert the string value to 0 whenever its null.

int block_id = Converttoint(jsonarray.getJSONObject(i).getString("block_id")); 

Then the function convertToInt

 public static Integer convertToInt(String str) {     int n=0;   if(str != null) {       n = Integer.parseInt(str);   }     return n; } 

How should I change it, to make it work?

Answer 1

Simply use the built-in method JSONObject#getInt(String), it will automatically convert the value to an int by calling behind the scene Integer.parseInt(String) if it is a String or by calling Number#intValue() if it is a Number. To avoid an exception when your key is not available, simply check first if your JSONObject instance has your key using JSONObject#has(String), this is enough to be safe because a key cannot have a null value, either it exists with a non null value or it doesn't exist.

JSONObject jObj = jsonarray.getJSONObject(i); int block_id = jObj.has("block_id") ? jObj.getInt("block_id") : 0;