Printing with Argument Indices

An argument index is an optional decimal integer followed by a $ sign that indicates the position of the argument in the argument list. For example, lines 2021 and 2425 in Fig. 28.9 use argument index "1$" to indicate that all format specifiers use the first argument in the argument list. Argument indices enable programmers to reorder the output so that the arguments in the argument list are not necessarily in the order of their corresponding format specifiers. Argument indices also help avoid duplicating arguments. Figure 28.22 demonstrates how to print arguments in the argument list in reverse order using the argument index.

Figure 28.22. Reordering output with argument indices.

 1 // Fig. 28.22: ArgumentIndexTest
 2 // Reordering output with argument indices.
 3
 4 public class ArgumentIndexTest
 5 {
 6 public static void main( String args[] )
 7 {
 8 System.out.printf(
 9 "Parameter list without reordering: %s %s %s %s
",
10 "first", "second", "third", "fourth" );
11 System.out.printf(
12 "Parameter list after reordering: %4$s %3$s %2$s %1$s
",
13 "first", "second", "third", "fourth" );
14 } // end main
15 } // end class ArgumentIndexTest
 
Parameter list without reordering: first second third fourth
Parameter list after reordering: fourth third second first
 

Introduction to Computers, the Internet and the World Wide Web

Introduction to Java Applications

Introduction to Classes and Objects

Control Statements: Part I

Control Statements: Part 2

Methods: A Deeper Look

Arrays

Classes and Objects: A Deeper Look

Object-Oriented Programming: Inheritance

Object-Oriented Programming: Polymorphism

GUI Components: Part 1

Graphics and Java 2D™

Exception Handling

Files and Streams

Recursion

Searching and Sorting

Data Structures

Generics

Collections

Introduction to Java Applets

Multimedia: Applets and Applications

GUI Components: Part 2

Multithreading

Networking

Accessing Databases with JDBC

Servlets

JavaServer Pages (JSP)

Formatted Output

Strings, Characters and Regular Expressions

Appendix A. Operator Precedence Chart

Appendix B. ASCII Character Set

Appendix C. Keywords and Reserved Words

Appendix D. Primitive Types

Appendix E. (On CD) Number Systems

Appendix F. (On CD) Unicode®

Appendix G. Using the Java API Documentation

Appendix H. (On CD) Creating Documentation with javadoc

Appendix I. (On CD) Bit Manipulation

Appendix J. (On CD) ATM Case Study Code

Appendix K. (On CD) Labeled break and continue Statements

Appendix L. (On CD) UML 2: Additional Diagram Types

Appendix M. (On CD) Design Patterns

Appendix N. Using the Debugger

Inside Back Cover



Java(c) How to Program
Java How to Program (6th Edition) (How to Program (Deitel))
ISBN: 0131483986
EAN: 2147483647
Year: 2003
Pages: 615

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