Difference between revisions of "Formatting"

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printf("format string", argument(s));
 
printf("format string", argument(s));
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== Format String ==
 
== Format String ==
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* Syntax:
 
* Syntax:
  
 
%[arg_index$][flags][width][.precision] conversion_char
 
%[arg_index$][flags][width][.precision] conversion_char
 +
 +
* Every argument must have a format string in the above syntax, or it wont be printed!
  
 
Arguments within [] are optional. Only the conversion_char is mandatory. The following are the conversion chars:  
 
Arguments within [] are optional. Only the conversion_char is mandatory. The following are the conversion chars:  
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</syntaxhighlight>
 
</syntaxhighlight>
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* flags
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** "-" : Left justify
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**
  
 
[[Category:OCPJP]]
 
[[Category:OCPJP]]

Revision as of 02:19, 8 July 2011

Introduction

  • String formatting can be done using the printf() and the format() methods added in java.io.PrintStream (System.out is a PrintStream)
  • Internally they ise the java.util.Formatter class.
  • Basic format:

printf("format string", argument(s));


Format String

  • Syntax:

%[arg_index$][flags][width][.precision] conversion_char

  • Every argument must have a format string in the above syntax, or it wont be printed!

Arguments within [] are optional. Only the conversion_char is mandatory. The following are the conversion chars:

  • b - boolean
  • c - char
  • d - integer
  • f - floating point
  • s - string

Optional arguments

  • arg_index is the number of the argument followed by a $. The no starts from 1.
System.out.printf("%2$s , %1$s", "Suhrid", "Karthik");
//Prints : Karthik, Suhrid
  • flags
    • "-" : Left justify