Convert 1 to 01

Question

I have an int between 1 - 99. How do I get it to always be a double digit, ie: 01, 04, 21?

Answer 1

You can do this with NumberFormat:

NumberFormat format = new NumberFormat();
format.setMinimumIntegerDigits(2);
System.out.println(format.format(1));

Note - String.format() is a Java 5 method.

If you're using Java 5 or above you can do:

String.format("%02d", 1);

as mentioned in other answers.