如何使用printf将单独的字符串格式化为一行？

Question

I am using a while loop and getting data from a text file and using classes to reference each string. I don't have any issues getting the values for each string and printing it out.

However, I am confused on how to use System.out.printf(....) to put all of the strings I need in one line while using a loop.

For example, let's say the text file was:

I
like
to
use
computers

I want to use a loop to print out the words into one string and I may have different spacing between each word.

The code I have so far:

while (!readyOrder.isEmpty()) {
    s = readyOrder.poll();
    System.out.printf(s.getQuantity() + " x " + s.getName()
        + "(" + s.getType() + ")" + "                "
        + s.getPrice() * s.getQuantity());
    System.out.println(" ");
    total = total + s.getPrice() * s.getQuantity();
}

And the output should be:

1_x_The Shawshank Redemption_______(DVD)________________19.95

The underlined spaces are where the spaces should be and how long they should be.

How can I use printf to do that?

Answer 1

I think you need to use the string padding functionality of printf. For example %-30s formats to width of 30 characters, - means left justify.

for (Stock s : Arrays.asList(
        new Stock(1, "The Shawshank Redemption", 100, "DVD"), 
        new Stock(2, "Human Centipede", 123, "VHS"),
        new Stock(1, "Sharknado 2", 123, "Blu ray"))) {

    System.out.printf("%2d x %-30s (%-7s) %5.2f\n",
            s.getQuantity(), s.getName(), s.getType(),
            s.getPrice() * s.getQuantity());
}

Output

1 x The Shawshank Redemption       (DVD    ) 100.00
2 x Human Centipede                (VHS    ) 246.00
1 x Sharknado 2                    (Blu ray) 123.00