sdsu.io
Class Format

java.lang.Object
  |
  +--sdsu.io.Format

public class Format

extends java.lang.Object

A class for formatting numbers that follows printf conventions. Also implements C-like atoi and atof functions. This class appears in Core Java by Gary Cornell and Cay S. Horstmann. The following appears in the source code for this class:
Permission to use, copy, modify, and distribute this software and its documentation for NON-COMMERCIAL purposes and without fee is hereby granted provided that this copyright notice appears in all copies.
THE AUTHORS AND PUBLISHER MAKE NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. THE AUTHORS AND PUBLISHER SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.

Version:

1.01 15 Feb 1996

Author:

Cay Horstmann

Constructor Summary

Format(java.lang.String s)
Formats the number following printf conventions.

Method Summary

static double	atof(java.lang.String s) Converts a string of digits to an double
static int	atoi(java.lang.String s) Converts a string of digits (decimal, octal or hex) to an integer
static long	atol(java.lang.String s) Converts a string of digits (decimal, octal or hex) to a long integer
java.lang.String	form(char c) Formats a character into a string (like sprintf in C)
java.lang.String	form(double x) Formats a double into a string (like sprintf in C)
java.lang.String	form(long x) Formats a long integer into a string (like sprintf in C)
java.lang.String	form(java.lang.String s) Formats a string into a larger string (like sprintf in C)
static void	main(java.lang.String[] a) a test stub for the format class
static void	print(java.io.PrintStream s, java.lang.String fmt, char x) prints a formatted number following printf conventions
static void	print(java.io.PrintStream s, java.lang.String fmt, double x) prints a formatted number following printf conventions
static void	print(java.io.PrintStream s, java.lang.String fmt, long x) prints a formatted number following printf conventions
static void	print(java.io.PrintStream s, java.lang.String fmt, java.lang.String x) prints a formatted number following printf conventions

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Format

public Format(java.lang.String s)

Formats the number following printf conventions. Main limitation: Can only handle one format parameter at a time Use multiple Format objects to format more than one number

Parameters:

s - the format string following printf conventions The string has a prefix, a format code and a suffix. The prefix and suffix become part of the formatted output. The format code directs the formatting of the (single) parameter to be formatted. The code has the following structure

• a % (required)
• a modifier (optional)

  +

  forces display of + for positive numbers

  0

  show leading zeroes

  -

  align left in the field

  space

  prepend a space in front of positive numbers

  #

  use "alternate" format. Add 0 or 0x for octal or hexadecimal numbers. Don't suppress trailing zeroes in general floating point format.

• an integer denoting field width (optional)
• a period followed by an integer denoting precision (optional)
• a format descriptor (required)

  f

  floating point number in fixed format

  e, E

  floating point number in exponential notation (scientific format). The E format results in an uppercase E for the exponent (1.14130E+003), the e format in a lowercase e.

  g, G

  floating point number in general format (fixed format for small numbers, exponential format for large numbers). Trailing zeroes are suppressed. The G format results in an uppercase E for the exponent (if any), the g format in a lowercase e.

  d, i

  integer in decimal

  x

  integer in hexadecimal

  o

  integer in octal

  s

  string

  c

  character

Throws:

java.lang.IllegalArgumentException - if bad format

Method Detail

print

public static void print(java.io.PrintStream s,
                         java.lang.String fmt,
                         double x)

prints a formatted number following printf conventions

Parameters:

s - a PrintStream

fmt - the format string

x - the double to print

print

public static void print(java.io.PrintStream s,
                         java.lang.String fmt,
                         long x)

prints a formatted number following printf conventions

Parameters:

s - a PrintStream

fmt - the format string

x - the long to print

print

public static void print(java.io.PrintStream s,
                         java.lang.String fmt,
                         char x)

prints a formatted number following printf conventions

Parameters:

s - a PrintStream

fmt - the format string

x - the character to

print

public static void print(java.io.PrintStream s,
                         java.lang.String fmt,
                         java.lang.String x)

prints a formatted number following printf conventions

Parameters:

s - a PrintStream, fmt the format string

x - a string that represents the digits to print

atoi

public static int atoi(java.lang.String s)

Converts a string of digits (decimal, octal or hex) to an integer

Parameters:

s - a string

Returns:

the numeric value of the prefix of s representing a base 10 integer

atol

public static long atol(java.lang.String s)

Converts a string of digits (decimal, octal or hex) to a long integer

Parameters:

s - a string

Returns:

the numeric value of the prefix of s representing a base 10 integer

atof

public static double atof(java.lang.String s)

Converts a string of digits to an double

Parameters:

s - a string

form

public java.lang.String form(double x)

Formats a double into a string (like sprintf in C)

Parameters:

x - the number to format

Returns:

the formatted string

Throws:

java.lang.IllegalArgumentException - if bad argument

form

public java.lang.String form(long x)

Formats a long integer into a string (like sprintf in C)

Parameters:

x - the number to format

Returns:

the formatted string

form

public java.lang.String form(char c)

Formats a character into a string (like sprintf in C)

Parameters:

x - the value to format

Returns:

the formatted string

form

public java.lang.String form(java.lang.String s)

Formats a string into a larger string (like sprintf in C)

Parameters:

x - the value to format

Returns:

the formatted string

main

public static void main(java.lang.String[] a)

a test stub for the format class