Double % formatting question for printf in Java

Question

%s is a string in printf, and %d is a decimal I thought...yet when putting in

writer.printf(\"%d dollars is the balance of %s\\r\\         


        

Answer 1

Yes, %d means decimal, but it means decimal number system, not decimal point.

Further, as a complement to the former post, you can also control the number of decimal points to show. Try this,

System.out.printf("%.2f %.1f",d,f); // prints 1.20 1.2

For more please refer to the API docs.