Variable Assignment and loops (Java)
- by Raven Dreamer
Greetings Stack Overflowers,
A while back, I was working on a program that hashed values into a hashtable (I don't remember the specifics, and the specifics themselves are irrelevant to the question at hand). Anyway, I had the following code as part of a "recordInput" method.
tempElement = new hashElement(someInt);
while(in.hasNext() == true)
{
int firstVal = in.nextInt();
if (firstVal == -911)
{
break;
}
tempElement.setKeyValue(firstVal, 0);
for(int i = 1; i<numKeyValues;i++)
{
tempElement.setKeyValue(in.nextInt(), i);
}
elementArray[placeValue] = tempElement;
placeValue++;
} // close while loop
} // close method
This part of the code was giving me a very nasty bug -- no matter how I finagled it, no matter what input I gave the program, it would always produce an array full of only a single value -- the last one.
The problem, as I later determined it, was that because I had not created the tempElement variable within the loop, and because values were not being assigned to elementArray[] until after the loop had ended -- every term was defined rather as "tempElement" -- when the loop terminated, every slot in the array was filled with the last value tempElement had taken.
I was able to fix this bug by moving the declaration of tempElement within the while loop. My question to you, Stackoverflow, is whether there is another (read: better) way to avoid this bug while keeping the variable declaration of tempElement outside the while loop.
(suggestions for better title and tags also appreciated)
