variable Initialisation in JSP

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Views: 1524 | Replies: 3

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Join Date: Dec 2006

Posts: 54

Reputation: staneja is an unknown quantity at this point

Rep Power: 2

Solved Threads: 1

staneja

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Junior Poster in Training

variable Initialisation in JSP

Mar 16th, 2007

I am new to JSP and was trying a very simple program that adds/Divide/multiply/Subtract 2 numbers
I am taking two numbers from a web page and as per the button pressed performing the action on JSP page. I have kept a vraiable c for output

If i write int c=0 ;then it works fine but if i only write int c and then code its not working
I have never observed this behavior in core Java.Is variable initialisation is mandatory in JSP.FOllowing is code i am using that throws exception

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 <body><% 
            int a=Integer.parseInt(request.getParameter("t1"));
            int b=Integer.parseInt(request.getParameter("t2"));
            int c ;
            String label=request.getParameter("b1");
            if (label.equals("add"))
                c=a+b;
            else
                if (label.equals("sub"))
                c=a-b;
                else
                    if (label.equals("mul"))
                    c=a*b;
                    else
                        if (label.equals("div"))
                        c=a/b;
        %>
         <% out.print(c);%>
    </body>

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Join Date: Feb 2006

Posts: 1,469

Reputation: masijade is just really nice

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masijade

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Nearly a Posting Virtuoso

Re: variable Initialisation in JSP

Mar 16th, 2007

What happens, if it makes it all the way to the last nested if statement and that statement evaluates to false instead of true? What value would c have then? None because it hasn't been initialised. Add an else to the last nested if and the error will go away.

Java Programmer and Sun Systems Administrator

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Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it.
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