exceptions

[aparna rudra]

wpould anyone tell me wht is the output? and how does the control execution takes place.

class Level1Exception extends Exception {}
class Level2Exception extends Level1Exception {}
class Level3Exception extends Level2Exception {}
class Purple {
public static void main(String args[]) {
int a,b,c,d,f,g,x;
a = b = c = d = f = g = 0;
x = 1;
try {
try {
switch (x) {
case 1: throw new Level1Exception();
case 2: throw new Level2Exception();
case 3: throw new Level3Exception();
} a++; }
catch (Level2Exception e) {b++;}
finally {c++;}
}
catch (Level1Exception e) { d++;}
catch (Exception e) {f++;}
finally {g++;}
System.out.print(a+","+b+","+c+","+d+","+f+","+g);
}}

[Peter van de Riet]

output is 0,0,1,1,0,1
In the inner try is Level1Exception thrown. Because of this exception the next 2 case staments are not executed (break is missing, normally a fall-through would happen).
The Level1Exception is not caught in the catch clause from the inner try. The (inner try) finally of course is executed (c++). The catch Level1Exception from the outer try catches the exception and executes (d++). After a catch the next catches are not evaluated and the (outer try) finally is executed (g++).
The output therefore is as I wrote in the first line.

Peter

[Andris Jekabsons]

Try modifying the code smth like this:

class Level1Exception extends Exception {}
class Level2Exception extends Level1Exception {}
class Level3Exception extends Level2Exception {}
 
class Purple
{
    static int a, b, c, d, f, g, x;
 
    public static void main( String args[] )
    {
        a = b = c = d = f = g = 0;
        x = 1;
 
        try
        {
            try
            {
                switch ( x )
                {
                    case 1: throw new Level1Exception();
                    case 2: throw new Level2Exception();
                    case 3: throw new Level3Exception();
                }
                a++;
                print( "exit switch" );
            }
            catch ( Level2Exception e )
            {
                b++;
                print( "catch Level2Exception" );
            }
            finally
            {
                c++;
                print( "finally1" );
            }
        }
        catch ( Level1Exception e )
        {
            d++;
            print( "catch Level1Exception" );
        }
        catch ( Exception e )
        {
            f++;
            print( "catch Exception" );
        }
        finally
        {
            g++;
            print( "finally2" );
        }
        print( "\nEND" );
        System.out.print( '\n' );
    }
 
    private static void print( String msg )
    {
        System.out.print( msg + ":: a=" + a + "; b=" + b + "; c=" + c + "; d=" +
            d + "; f=" + f + "; g=" + g + "\n");
    }
}

and then compile and run it. See what you get for yourself!
P.S. When posting a code, don't just paste it, but it in in the CODE UBB tags.

[subu ananthram]

class Level1Exception extends Exception {}
class Level2Exception extends Level1Exception {}
class Level3Exception extends Level2Exception {}
class Purple {
public static void main(String args[]) {
int a,b,c,d,f,g,x;
a = b = c = d = f = g = 0;
x = 1;
try {
try {
switch (x) {
case 1: throw new Level1Exception();
case 2: throw new Level2Exception();
case 3: throw new Level3Exception();
} a++; }
catch (Level2Exception e) {b++;}
finally {c++;}
}
catch (Level1Exception e) { d++;}
catch (Exception e) {f++;}
finally {g++;}
System.out.print(a+","+b+","+c+","+d+","+f+","+g);
}}

initially x=1 enters nested try
and throws Level1Exception() then you look for a catch block to handle that exception no such catch implement finally goes to outer catch handles exception implements finally
so you get the answer as 001101
i hope that answers your question
regards
priya