Question

Not sure what I’m doing wrong here. But I want to change the card to the correct format.

For example given the card 1c change it to AC.

Here’s some code I’ve been playing with:

public static void main(String[] args) {

    String[] cards = {"1c", "13s"};

    for (String card : cards) {

        switch (card.toUpperCase()) {
            case "1C":
                card = card.toUpperCase().replace("1C", "AC");
                break;
            case "13S":
                card = card.toUpperCase().replace("13S", "KS");
                break;
            default:
                System.out.println(Arrays.toString(cards));
        }
    }
    System.out.println(Arrays.toString(cards));

}

Any help would be great cheers.

Answer 1

Within the loop, card is just a local variable, and reassigning it doesn’t modify the array cards. An immediate fix would be to index over the array so you can reference each element directly:

for (int i = 0; i < cards.length; i++) {
    switch (cards[i].toUpperCase()) {
        case "1C":
            cards[i] = cards[i].toUpperCase().replace("1C", "AC");
            break;
        case "13S":
            cards[i] = cards[i].toUpperCase().replace("13S", "KS");
            break;
        default:
            System.out.println(Arrays.toString(cards));
    }
}

Edit: to answer edhedges’ comment, one would need to keep a counter variable outside the loop in order to keep using the enhanced-for syntax:

int i = 0;
for (String card : cards) {
    switch (card.toUpperCase()) {
        case "1C":
            cards[i] = card.toUpperCase().replace("1C", "AC");
            break;
        case "13S":
            cards[i] = card.toUpperCase().replace("13S", "KS");
            break;
        default:
            System.out.println(Arrays.toString(cards));
    }
    i++;
}