Table of Contents

format

format args to the format string format and write the result to the stream 

format(String format, Object... args);
 
return value: stream
sign Description
0 if the place is not busy they prints a 0
# if the place is not busy they prints nothing
. decimal separator Separates and decimal places.
, Groups the numbers (a group is as large as the distance from ”,” to ”.”).
; Delimiter. To the left of the pattern is positive, the right for negative numbers.
- The default character for the negative prefix
% The number is multiplied by 100 and reported as a percentage.
% % (without the space )Just like %, with only thousandths.
\uXXXX unicode XXXX stands for Numbers and chars like \u20B3
' Masking of special symbols in the prefix or suffix
%n new line
%b Boolean
%% Percent
%s String
%c Unicode-Char
%d decimaldigit
%x hexadecimal
%t Date / Time
%f Float
%e scientific notation

Language Example

package codereferececomjava;
 
public class CodeRefereceComJava {
 
 
    public static void main(String[] args) {
 
    String strout = null;
    String str = "is the answer";
    int i = 42;
    String[] arguments = { "way", "example" };
 
    strout = String.format("%d %s", i, str);
    System.out.println(strout);
 
    strout = String.format( "this is another %s for this %s.\n", arguments ); 
    System.out.println(strout);
 
    double  ans = 42.1234568;
 
    System.out.format("The answer is probably %.0f", ans);
    System.out.format("\t and not %.2f \n", ans);
    System.out.format("also not %1.2f \n", ans); // prints 1
 
 
    String string = "hey";
    System.out.format("%-10s reserve 10 signs on the right side\n", string );
    System.out.format("%20s reserve 10 signs on the left side\n", string );
 
    System.out.format("%10d reserve 10 signs for the number \n", i );
    System.out.format("%+d print math signs \n", i ); // print math signs 
    System.out.format("%010d reserve 10 places and fill it with 0\n", i );
 
    System.out.format("%,2.3f special character \n", ans );
 
 
 }
}

output

  The answer is probably 42	 and not 42,12 
  also not 42,12 
  hey        reserve 10 signs on the right side
                   hey reserve 10 signs on the left side
          42 reserve 10 signs for the number 
  +42 print math signs 
  0000000042 reserve 10 places and fill it with 0
  42,123 special character

2nd format example in java

package codereferececomjava;
 
public class CodeRefereceComJava {
 
 
    public static void main(String[] args) {
 
        int dnumber = - 5;
        double fnumber = 12317.27;
        String str = "Number";
        char ch = 'A';
        System.out.format("%-30s : %-+10d : %c : %,15.1f\n", str, dnumber, ch, fnumber);
 }
}

output of 2nd format example

   Number                         : -5         : A :        12.317,3