Java Formatting - Some data are not aligned

Question

it's my first time to do java. We are currently learning it but we have not really touched up on formatting and i was wondering if anyone could help me with my code. So my code is as follows:

public void displayAllOrder()
{
    System.out.println("Initial Cost" + "\t" + "Voucher Code Used" + "\t" + "Voucher Amount Deducted" + "\t\t" + "Final Cost" + "\t" + "Shipping ID" + "\t" + "Shipment Status");
    for (int i = 0; i <= currentIndex; i++)
    {
        String strInitialCost = String.format("%.2f", initialCost[i]);
        String strFinalCost = String.format("%.2f", finalCost[i]);
        System.out.println("$"+strInitialCost + "\t\t" + voucherCode[i] + "\t\t\t" + "$"+voucherAmount[i] + "\t\t\t" + "$"+strFinalCost + "\t" + shippingID[i] + "\t\t" + shipmentStatus[i]);
    }

It aligns perfectly if the input is large but it is not aligned if the calculated input is small. Example output as follows:

I hope someone could help me understand with regards to this issue. Thank you.

Tabs are finicky and it is better to use spaces for alignment. You also need to be sure your font is monospaced. The String.format method supports field sizes that can help with this. The code %10s will print one argument padded to at least size 10. It won't truncate, though. — Christopher, Sep 17 '21 at 13:52
I think the problem is not java, if you try to write the same thing in a notepad for example, you are going to have the same problem. Therefore if you want always everything to be aligned, you have to calculate the tabs depending on the input. — William Andrés Bernal, Sep 17 '21 at 13:52
Don't use tabs to align output. See [this](https://stackoverflow.com/questions/3450758/string-format-to-fill-a-string) answer — krankkk, Sep 17 '21 at 13:53
You also need to be aware of the difference of left alignment or right alignment, which just means you put the extra spaces on the left or right to pad a field to a column width. — Christopher, Sep 17 '21 at 13:53
change the voucher code from 0 to 0000, that would align rest of format — sanjeevRm, Sep 17 '21 at 13:53

score 2 · Answer 1 · answered Sep 17 '21 at 14:32

Maybe you even want a different output type.

When it's about layout maybe you want to put it in an html table and watch it with a browser:

public void displayAllOrder()
{
    System.out.println("<html><table><thead><tr>");
    for(String title : Arrays.asList("Initial Cost", "Voucher Code Used", "Voucher Amount Deducted", "Final Cost", "Shipping ID", "Shipment Status"))
    {
        printCell(title);
    }
    System.out.println("</tr></thead><tbody>");
    for (int i = 0; i <= currentIndex; i++)
    {
        System.out.println("<tr>");
        String strInitialCost = String.format("%.2f", initialCost[i]);
        String strFinalCost = String.format("%.2f", finalCost[i]);
        printCell("$"+strInitialCost);
        printCell(voucherCode[i]);
        printCell("$"+voucherAmount[i]);
        printCell("$"+strFinalCost);
        printCell(shippingID[i]);
        printCell(shipmentStatus[i]);
        System.out.println("</tr>");
    }
    System.out.println("</tbody></table></html>");
}

private void printCell(String content)
{
    System.out.println("<td>" + content + "</td>");
}

score 1 · Accepted Answer · answered Sep 17 '21 at 14:14

For a fixed sized font where every character has the same width ("m" and "i"), you can use printf with something like %13.2f for a 13 positions right aligned double.

public void displayAllOrders() {
    System.out.printf("%-15s %-15s %-20s %-15s %-15s %s%n",
        "Initial Cost", "Voucher Code Used", "Voucher Amount Deducted",
        "Final Cost", "Shipping ID", "Shipment Status");
    for (int i = 0; i <= currentIndex; i++) {
        System.out.printf("$-14.2f %-15s %5s$%14.2f $%14.2f %-15s %s%n",
          initialCost[i], voucherCode[i], "", voucherAmount[i],
          finalCost[i], shippingID[i], shipmentStatus[i]);
    }
}

The above code might be wrong, and I do not know the widths needed: columns 15 wide, one space between them. %n = end of line.

Using tabs, "\t" will on Windows pad to 8 spaces. That will lead to unnerving layouting.

Java Formatting - Some data are not aligned

2 Answers2