scope of a variable

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Kenneth - 06 Dec 2004 05:53 GMT

I want to know why the variable 'i' is not recognized within the 'try'
function? The code is below:

for(int i =1; i<stock.length;i++)
{

    System.out.print("Input the price: ");
    System.out.flush();
    try {
            if ((line = stndin.readLine()) != null)
            stock[1].price = Double.valueOf(line).intValue();
        } catch (IOException e) {
        }
    System.out.print("Input the quantity: ");
    System.out.flush();
    try {
            if ((line = stndin.readLine()) != null)
            stock[i].quantity = Integer.valueOf(line).intValue();
        } catch (IOException e) {
        }


    System.out.println("buy " + stock[i].quantity + " at $" +
stock[i].price + " each.");
}

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Brett Foster - 06 Dec 2004 06:55 GMT

> I want to know why the variable 'i' is not recognized within the 'try'
> function? The code is below:

It's hard enough to debug code... It's next to impossible when you don't
even declare all your variables in the fragment.

**snip**

Think again:

for(int i =1; i<100;i++){
try {i=i;} catch (Exception ex) {};
}

You need to ISOLATE the problem. That is, take out as much code as
possible and begin to add it back in slowly and then see where you're
having trouble. I think you'll find it's not i.

Brett

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Ryan Stewart - 06 Dec 2004 12:21 GMT

>> I want to know why the variable 'i' is not recognized within the 'try'
>> function? The code is below:
>
> It's hard enough to debug code... It's next to impossible when you don't
> even declare all your variables in the fragment.

It's also much easier when you follow code standards:
http://java.sun.com/docs/codeconv/html/CodeConvTOC.doc.html

It makes your code much easier to read.

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Kenneth - 06 Dec 2004 23:11 GMT

> I want to know why the variable 'i' is not recognized within the 'try'
> function? The code is below:
[quoted text clipped - 21 lines]
> stock[i].price + " each.");
> }

brett, i don't understand what you're trying to say. i want to replace
all 'stock[1]' with 'stock[i]']. i need to use the 'i' that i declared
in the 'for' loop.

how do i reference that 'i'?

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Eric Sosman - 06 Dec 2004 23:24 GMT

> brett, i don't understand what you're trying to say. i want to replace
> all 'stock[1]' with 'stock[i]']. i need to use the 'i' that i declared
> in the 'for' loop.
>
> how do i reference that 'i'?

Exactly as you're doing in the "stock[i].quantity="
line and in the final println() call. Just change the
"stock[1].price=" to "stock[i].price=" and you're set.

If that doesn't cure your problems, you'll have to
explain what problems you're having. So far, you have
not done so, nor shown enough code for anyone to guess
what they might be. Please see

http://www.physci.org/codes/sscce.jsp

Signature

Eric.Sosman@sun.com

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Kenneth - 07 Dec 2004 00:15 GMT

>>brett, i don't understand what you're trying to say. i want to replace
>>all 'stock[1]' with 'stock[i]']. i need to use the 'i' that i declared
[quoted text clipped - 12 lines]
>
> http://www.physci.org/codes/sscce.jsp

the compiler error i recieve is: 'variable 'i' not initialized'

here is the code again;

for(int i =1; i<stock.length;i++)
{
System.out.print("Input the price: ");
    System.out.flush();
    try {
            if ((line = stndin.readLine()) != null)
            stock[i].price = Double.valueOf(line).intValue();
        } catch (IOException e) {
        }
    System.out.print("Input the quantity: ");
    System.out.flush();
    try {
            if ((line = stndin.readLine()) != null)
            stock[i].quantity = Integer.valueOf(line).intValue();
        } catch (IOException e) {
        }


    System.out.println("buy " + stock[i].quantity + " at $" +
stock[i].price + " each.");
}

is it because the 'i' variable is in the try() statement? if so how
would i reference the declared 'i' in the for loop in the try()
statement?

since i delcared 'i' to be 1 in the for() statement, when 'i' goes
through the try() statements, 'i' should be 1, right?

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Andrew Thompson - 07 Dec 2004 00:29 GMT

>> http://www.physci.org/codes/sscce.jsp

> the compiler error i recieve is: 'variable 'i' not initialized'

...

> here is the code again;
>
> for(int i =1; i<stock.length;i++)

A quiz for you Kenneth. What do the second S and first C
os SSCCE mean? Why are they important?

Signature

Andrew Thompson
http://www.PhySci.org/codes/ Web & IT Help
http://www.PhySci.org/ Open-source software suite
http://www.1point1C.org/ Science & Technology
http://www.LensEscapes.com/ Images that escape the mundane

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Kenneth - 07 Dec 2004 20:31 GMT

>>> brett, i don't understand what you're trying to say. i want to
>>> replace all 'stock[1]' with 'stock[i]']. i need to use the 'i' that
[quoted text clipped - 44 lines]
> since i delcared 'i' to be 1 in the for() statement, when 'i' goes
> through the try() statements, 'i' should be 1, right?

for some reason, the error message is gone. now it goes through the
loop once and the second time around it just stops at
"System.out.print("Input the quantity: ");"

any ideas what might be going on?

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scope of a variable

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