While working on a code, I was wondering if I could avoid try n catch and used something else. For example, if i have a value(from console) of type double and if user enters a string or something else then there should be a prompt to re-enter the value.
I know this can be done very easily using try-n-catch but how can we do it without it, is there any way out?
Please give an example if possible.
Sadly, the JDK lacks the TryParse method that some other libraries provide. I wouldn't be surprised to find something in Apache Commons or Guava that does it.
Alternately, you might use a Scanner and use its hasNextDouble to do the check.
If you're asking how to avoid dealing with exceptions in general: Don't try. Exceptions are a powerful way of handling exceptional conditions in programs, and the "handle-or-declare" provided by checked exceptions (e.g., your code must handle the exception, or declare that it doesn't) is very useful.
But there are some use-cases, like your example, where you might well want to avoid an exception being thrown because, after all, a user entering invalid input isn't an exceptional condition, it's an all-too-common one. :-)
Throw Exceptions are less robust but a good way to deal avoiding with try/catch statements.
import java.io.*;
public class UsingThrows {
public static void main(String args[]) throws FileNotFoundException {
FileInputStream fis = new FileInputStream("def.txt");
System.out.println("OK 1");
}
}
doublevalidation. It's quite a roundabout way of second-guessingparseDoubles result, and it's complex. There's scientific notation, four different limits to check, ...