So when I do a code of blocks inside a try{}
, and I try to return
a value, it tells me
no return values
import org.w3c.dom.ranges.RangeException;
public class Pg257E5
{
public static void main(String[]args)
{
try
{
System.out.println(add(args));
}
catch(RangeException e)
{
e.printStackTrace();
}
finally
{
System.out.println("Thanks for using the program kiddo!");
}
}
public static double add(String[] values)
// shows a commpile error here that I don't have a return value
{
try
{
int length = values.length;
double arrayValues[] = new double[length];
double sum = 0;
for(int i = 0; i<length; i++)
{
arrayValues[i] = Double.parseDouble(values[i]);
sum += arrayValues[i];
}
return sum; // I do have a return value here.
// Is it because if the an exception occurs the codes in try stops and doesn't get to the return value?
}
catch(NumberFormatException e)
{
e.printStackTrace();
}
catch(RangeException e)
{
throw e;
}
finally
{
System.out.println("Thank you for using the program!");
//so would I need to put a return value of type double here?
}
}
}
My question is, how do you return a value when you are using try
and catch
?
This question is related to
java
exception
double
try-catch
return-value
The problem is what happens when you get NumberFormatexception
thrown? You print it and return nothing.
Note: You don't need to catch and throw an Exception back. Usually it is done to wrap it or print stack trace and ignore for example.
catch(RangeException e) {
throw e;
}
Here is another example that return's a boolean value using try/catch.
private boolean doSomeThing(int index){
try {
if(index%2==0)
return true;
} catch (Exception e) {
System.out.println(e.getMessage());
}finally {
System.out.println("Finally!!! ;) ");
}
return false;
}
It is because you are in a try
statement. Since there could be an error, sum might not get initialized, so put your return statement in the finally
block, that way it will for sure be returned.
Make sure that you initialize sum outside the try/catch/finally
so that it is in scope.
Source: Stackoverflow.com