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 S

Answer 1

String toBeParsedStr="1234";
int parsedInt=toBeParsedStr!=null&&toBeParsedStr.matches("[0-9]+")?Integer.parseInt(toBeParsedStr):0;

Answer 2

you can use Integer.getInteger("30").intValue()

Answer 3

int block_id_0 = jObj.optInt("block_id"); 

The ternary condition and multiple code can simply be replaced with optInt function in a single line, which simply

1.) return the default value or 0 if no value is there (depends upon the variant you are using).

2.) Try to convert the value, if the value is available as string

3.) Simply No null or NumberFormat exceptions at all in case of missing key or value

Android docs

int optInt (String name)

int optInt (String name, int fallback)

Maven-Central

int optInt(String key, int defaultValue)

To get a specified default value if no value available

Get an optional int value associated with a key, or the default if there is no such key or if the value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.

jObj.optInt("block_id",defaultvalue);

or

To get a default value as 0 if no value available

Get an optional int value associated with a key, or zero if there is no such key or if the value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.

jObj.optInt("block_id");

e.g

int block_id = jObj.optInt("block_id",5); 

block_id will be 5 if no key/value available

int block_id_0 = jObj.optInt("block_id"); 

block_id_0 will be 0 if no key/value available

There are other variant of this function available for other datatypes as well , try the docs link above.

Answer 4

String str = "...";
// suppose str becomes null after some operation(s).
int number = 0;
try
{
    if(str != null)
      number = Integer.parseInt(str);
}
catch (NumberFormatException e)
{
    number = 0;
}

Answer 5

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;

Answer 6

There is one more way to do this apart from the methods given in rest of the answers.

String blockId=jsonarray.getJSONObject(i).getString("block_id");
int block_id = blockId==null ? 0 :  Integer.parseInt(blockId);