MATHEMATICAL FUNCTIONS, CHARACTERS, AND STRINGS - Introduction to Java Programming: Comprehensive Version - page 148

Caution
The items must match the format specifiers in exact type. The item for the format
specifier %f or %e must be a floating-point type value such as 40.0 , not 40 . Thus, an
int variable cannot match %f or %e .

Tip
The % sign denotes a format specifier. To output a literal % in the format string, use %% .

Listing 4.6 gives a program that uses printf to display a table.

L ISTING 4.6

FormatDemo.java
1 public class FormatDemo {
2 public static void main(String[] args) {

3 // Display the header of the table

4 System.out.printf( "%-10s%-10s%-10s%-10s%-10s\n" , "Degrees" , display table header

5 "Radians" , "Sine" , "Cosine" , "Tangent" );

6
7 // Display values for 30 degrees
8 int degrees = 30 ;
9 double radians = Math.toRadians(degrees);
10 System.out.printf( "%-10d%-10.4f%-10.4f%-10.4f%-10.4f\n" , degrees,
11 radians, Math.sin(radians), Math.cos(radians),
12 Math.tan(radians));
13
14 // Display values for 60 degrees
15 degrees = 60 ;
16 radians = Math.toRadians(degrees);
17 System.out.printf( "%-10d%-10.4f%-10.4f%-10.4f%-10.4f\n" , degrees,
18 radians, Math.sin(radians), Math.cos(radians),
19 Math.tan(radians));
20 }
21 }

values for 30 degrees

values for 60 degrees

Degrees Radians Sine Cosine Tangent
30 0.5236 0.5000 0.8660 0.5773
60 1.0472 0.8660 0.5000 1.7320

The statement in lines 4-5 displays the column names of the table. The column names are
strings. Each string is displayed using the specifier %-10s , which left-justifies the string. The
statement in lines 10-12 displays the degrees as an integer and four float values. The integer is
displayed using the specifier %-10d and each float is displayed using the specifier %-10.4f ,
which specifies four digits after the decimal point.

4.22

✓ ✓

What are the format specifiers for outputting a Boolean value, a character, a decimal
integer, a floating-point number, and a string?

Check

Point

4.23

What is wrong in the following statements?

(a) System.out.printf( "%5d %d" , 1 , 2 , 3 );

(b) System.out.printf( "%5d %f" , 1 );

(c) System.out.printf( "%5d %f" , 1 , 2 );