Java String.format adding spaces to integers

Question

I have a small piece of code that i don't understand the output.

This output is adding spaces to my string format text. I'm doing something wrong?

public class HelloWorld{

     public static void main(String []args){
        int a1 = 540;
        int a2 = 492;
        int a3 = 200;
        int a4 = 500;
        int a5 = 600;
        String a = "/share.html?title=%1s&description=%2s&image=%3s&width=%4s&height=%5s";
        String b = String.format(a, a1, a2, a3, a4, a5);
        System.out.println(b);
     }
}

The output is:

/share.html?title=540&description=492&image=200&width= 500&height=  600

Why there are those spaces on the last width and height?

I think you mean %1$s, %2$s, %3$s, %4$s etc. Or simply %s. — Andy Turner
– Andy Turner, Commented Jun 13, 2016 at 13:51

Andreas Fester · Accepted Answer · 2016-06-13 14:42:16Z

6

Remove the numbers from your format specifiers:

String a = "/share.html?title=%s&description=%s&image=%s&width=%s&height=%s";

Using a numerical value inside the format specifier like you did, you are specifying the minimal width of the output - this is the reason why you do not see any spaces for your first three values.

If you want to reference a particular parameter instead of letting the formatter evaluate them in the order they are specified, you can specify an argument index in the form n$ where n is the index of the referenced parameter (like 1$, 2$, ...).

See also java.util.Formatter for more information.

Instead of %s, you could also specify %d since all your arguments are of type int.

edited Jun 13, 2016 at 14:42

answered Jun 13, 2016 at 13:49

Andreas Fester

36.8k9 gold badges101 silver badges125 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Andy Turner Over a year ago

"Java's Formatter does not use position identifiers to reference the respective parameters" By default, yes. But you can specify the argument index.

Andreas Over a year ago

You should also suggest changing to %d, since the values are int.

Jens · Accepted Answer · 2016-06-13 13:50:18Z

2

Because you add Strings with lenght 4 and 5 and your values are ony 3 char.

You shoud use %d for formatting decimal.

The number in front of s is the length not the Position.

answered Jun 13, 2016 at 13:50

Jens

69.6k15 gold badges107 silver badges133 bronze badges

Comments

Andy Turner · Accepted Answer · 2016-06-13 13:58:57Z

2

The general structure of the format specifier is

%[argument_index$][flags][width][.precision]conversion

If you're trying to refer to argument indexes, you need a $ after the number, e.g.:

height=%5$s

However, since you're only using the parameters once, and in order, you can simply use:

height=%s

edited Jun 13, 2016 at 13:58

answered Jun 13, 2016 at 13:53

Andy Turner

141k11 gold badges169 silver badges263 bronze badges

Comments

Priyansh Goel · Accepted Answer · 2016-06-13 13:51:10Z

1

%4s means there should be total 4 characters outputted. And your number has 3 characters. So, it displays one " ". So, you need to remove all the numbers from format string.

answered Jun 13, 2016 at 13:51

Priyansh Goel

2,6701 gold badge17 silver badges37 bronze badges

1 Comment

Andreas Over a year ago

Not "total", but "at least".

Seek Addo · Accepted Answer · 2016-06-13 13:51:29Z

1

try this:

        int a1 = 540;
        int a2 = 492;
        int a3 = 200;
        int a4 = 500;
        int a5 = 600;
        String a = "/share.html?title=%s&description=%s&image=%s&width=%s&height=%s";
        String b = String.format(a, a1, a2, a3,a4,a5);
        System.out.println(b);

let me know if it works

answered Jun 13, 2016 at 13:51

Seek Addo

1,9033 gold badges22 silver badges31 bronze badges

Collectives™ on Stack Overflow

Java String.format adding spaces to integers

5 Answers 5

2 Comments

Comments

Comments

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

2 Comments

Comments

Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related