Adding elements before and after array

Hi all,

I'm new to Java and I'm having this problem with adding elements alternately in front and behind an array.

The methods to add the elements I have already figured out.

I also came up with a method to add the elements alternately to the array, but my instructor told me it could be done with a boolean instead of what I have now.

My method now is to keep up count when the data that needs to be added is read and whenever the count odd it adds data BEHIND and whenever it's even it adds data IN FRONT of the array.

Code:

---

in.useDelimiter("=");
               
                int count = 0;
               
                while (in.hasNext()) {
                        String array = in.next();
                        Scanner arrayScanner = new Scanner (array);
                        if (count%2==0) {
                                coordinateArrayInput.addInFrontArray(readArray(arrayScanner));
                        } else {
                                coordinateArrayInput.addBehindArray(readArray(arrayScanner));
                        }
                        count+=1;

---

Could anyone please tell me how to fix this problem with the boolean my instructor is talking about?

Thank you.

Yours,

liQuorice

Suppose you have a boolean flag; it can be either true or false; if it is true you add a value, say, to the front of the array, otherwise you append it to the end. You 'toggle' the value of that flag like this:

Code:

---

flag= !flag;

---

You have to do that as the last statement of the body of your loop and you have to initialize its value to true or false, depending on if you want to insert or append your first element.

kind regards,

Jos

Dear JosAH,

Thank you for your reply.

Unfortunately it was not the answer I was looking I for (I think...?).

My instructor told me you can do it with a boolean AND without the count to check if it's even or odd.

Still a mystery to me...anyone care to share their knowledge :)?

Thank you.

Yours,

liQuorice

i think you need to look at Jos' answer again. Unless I'm misunderstanding you're question, Jos' answer should do it.
Basically, he is suggesting this:

Code:

---

boolean flag = true;
while (in.hasNext()) {
    if (flag) {
        coordinateArrayInput.addInFrontArray(readArray(arrayScanner));
    } else {
        coordinateArrayInput.addBehindArray(readArray(arrayScanner));
    }
    flag = !flag;
}

---

This uses a boolean and doesnt use a counter.

Hope this explains it better!

Thank you berkeley and Jos!

This solves my problem....:D!

Yours,

liQuorice