Carey Brown

You might find the List#addAll() method to be useful. You can use it to make a new list but the contents of the new list will refer to the same objects of type "Long". Having the same reference to a Long is not a problem because a Long is immutable and cannot be modified.

Jonny Balcon wrote:It is a textbook exercise and it is  requirement I should execute a deep copy.

Can you tell us the source of the exercise and exactly what the requirements are?

Why do you think you need a "deep copy"? Or, for that matter, any copy at all?

Please UseCodeTags.

First question: does it compile?

Bill Platt wrote:What I want to do is remove the asterisks so that it reads as:

Warning! Problem detected!

Close. It should be:
       readTextFile[6] = readTextFile[6].replaceAll("\\*+", "");

Tim Moores wrote:I see, what you're asking is how to obtain the CPU and memory usage info for a chosen process. I'm not a Windows expert, but this discussion has a number of starting points on how to do that.

Discussion is from 2008. Perfmon.exe is still available in Win-10 but is a GUI with no API as far as I can tell. They also mention WMI which doesn't run on Win-10.

You'll need something with an API or at least log files.

You need some structure or Collection that represents the "state" of your bag. A part of the state needs to identify all the items in the bag at a given point in time and their sum weight and sum cost. You start out with an initial state for an empty bag.

You enter your recursive method with a state.
You look to see what you can add to the state that will not exceed the weight.
If that state has been tried before, return null.
If it is the exact weight, see of the cost is less than the last state that had the exact weight, then return the state.
If it is less than the weight, take the new state and pass it to the next call to the method.
If it is greater than the weight, return null.

The answer will be returned as you unwind the recursion back to the original call.

There are some subtleties not mentioned here, like, "almost" exact weight, but this is the general gist.

Knute Snortum wrote:...An entire table might be List<MyClass>.

Or a part of a table as returned by a query.
List<MyClass> results
As returned from a query "SELECT * FROM mytable WHERE something_is_true ORDER BY some_column"

Seems like the requirements are open to interpretation. All keyboard input comes in as characters.

You could get them as a list of numbers entered on a single line using Scanner#nextLine(), but then you'd have to separate then numbers and take each number (String) and parse it into an int (using Integer#parseInt()) for processing.

You could use Scanner#next() to split the numbers into individual Strings but then you'd still have to parse them into ints.

You could use Scanner#nextInt() which both splits the numbers and parses them into ints.

The last approach would be my preference but it depends on how you interpret the specs. With the last approach you end up with a list of ints that you can sum and count for your average but you'd have to print them to the display, which is trivial.

Sounds like an editor issue, not a Java issue.

What you are doing in your loop is:
Read [0]
   Print [0], Print[1], Print[2], Print[3], Print[4], Print[5]
Only [0] has been read so far so the others will be null.
Next time you
Read [1]
Now when you print, [0] contains your first read, [1] contains your second read, all the others are still null.

Why not just read "a String" and then print "a String"? No need for arrays.

What output were you expecting?

       while (countlines.hasNextLine()){            counter = counter+1 ;                         countlines.next();        }
You are testing with hasNextLine(), but in the loop you're not calling nextLine().
You also need to close the Scanner when you're done with it.

This is not doing what you think it's doing.
i=i++
Either use
i = i + 1
i += 1
or best
i++