— Scott McNealy, Sun Microsystems Chairman, President and ceo

“%d”
, 42);
The TYPE is mandatory, everything else is optional.
42
%d 
decimal
format(
“%.3f”
,
 
42.000000);
42.000
%f 
floating point
format(
“%x”
, 42);
2a
%x 
hexadecimal
format(
“%c”, 
42);
*
%c 
character
The argument must be compatible with an int, so that means 
only byte, short, int, and char (or their wrapper types).
The argument must be of a floating point type, so that 
means only a float or double (primitive or wrapper) as well 
as something called BigDecimal (which we don’t look at in 
this book).
A 42.25 would not work! It 
would be the same as trying to 
directly assign a double to an 
int variable.
Here we combined the “f” 
with a precision indicator 
“.3” so we ended up with 
three zeroes.
The argument must be a byte, short, int, long (including 
both primitive and wrapper types), and BigInteger. 
You must include a 
type in your format 
instructions, and if you 
specify things besides 
type, the type must 
always come last. 
Most of the time, 
you’ll probably format 
numbers using either 
“d” for decimal or “f” 
for f loating point.
The argument must be a byte, short, char, or int (including 
both primitive and wrapper types).
The number 42 represents 
the char “*”.

---

300
 
chapter 10
What happens if I have more than one argument?
Imagine you want a String that looks like this:
“The rank is 20,456,654 out of 100,567,890.24.”
But the numbers are coming from variables. What do you do? You simply add two 
arguments after the format String (first argument), so that means your call to format() 
will have three arguments instead of two. And inside that first argument (the format 
String), you’ll have two different format specifiers (two things that start with “%”). The 
first format specifier will insert the second argument to the method, and the second 
format specifier will insert the third argument to the method. In other words, the 
variable insertions in the format String use the order in which the other arguments are 
passed into the format() method.
int one = 20456654;
double two = 100567890.248907;
String s = String.format(“The rank is