CODEWITHSUNDEEP
javaarrays
user3033222
user3033222

Reputation: 1

Deleting an item from an array. (Java)

I'm working in Java right now, and I'm attempting to make an array copy itself into a temporary array, and then overwriting again with a new list, however the code isn't functioning.

MobilePhoneInventory.java

public void delete(MobilePhone p) {
    MobilePhone[] temp = new MobilePhone[list.length-1];
    int adj = 0;
    for (int i = 0; i < list.length; i++) {
        if (p != list[i]) {
            temp[i-adj] = list[i];
        }
        else adj = 1;
    }
    list = temp;
    numMobilePhone--;
}

MobilePhoneStart.java

    if (e.getSource() == myDelete) {
        if (inven.size() > 1) {
            inven.delete(inven.get(see));
            see--;
            if (see < 0) {
                see = 0;
            }
            showMP();
        } else {
            System.exit(0);
        }
    }

For some reason it's not creating the new list. Any ideas? Thanks in advance.

Upvotes: 0

Views: 104

Answers (1)

Rick-777
Rick-777

Reputation: 10268

When copying Java arrays, my preferred way is with System.arrayCopy. In your case, you have a test inside the loop which actually probably makes your approach more suitable.

Without seeing the rest of your class and how its mutable state works, it's hard to be sure about the solution. Overall, it looks OK. Possibly, there is a mistake with a reference somewhere so you don't get the thing you thought you'd got.

But one thing worth testing is that your equality test is the correct one:

if (p != list[i]) {

because you may find a ! ... .equals test works more reliably than !=.

Upvotes: 3

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