Convert a String to a Number
String to int
The static method
Integer.parseInt will do the trick
There is a danger that the string does not represent a valid number in which case an exception will be raised.
There are plenty of similar routines such as:
Float.parseFloat Long.parseLong Double.parseDouble
The value "1234" is a string, you need to treat it as a number - to add 1, giving 1235.