How to use java system.out.printf() [transfer]

1. public class  Main   
2. {  
3.     publicstaticvoid main(String[] args)    
4.     {  
5.         // Define some variables to format the output.  
6.         double d = 345.678;  
7.         String s =  "Hello!" ;  
8.         int i = 1234;  
9.         // "%" means formatted output, and the content after "%" is the definition of the format.  
10.         System.out.printf( "%f" , d); // "f" means formatted output float.  
11.         System.out.println();  
12.         System.out.printf( "%9.2f" , d); // The 9 in "9.2" is the length of the output, and the 2 is the number of digits after the decimal point.  
13.         System.out.println();  
14.         System.out.printf( "%+9.2f" , d); // "+" means the output number is signed.  
15.         System.out.println();  
16.         System.out.printf( "%-9.4f" , d); // "-" means that the output number is left-aligned (default is right-aligned).  
17.         System.out.println();  
18.         System.out.printf( "%+-9.3f" , d); // "+-" means the output number is signed and left justified.  
19.         System.out.println();  
20.         System.out.printf( "%d" , i); // "d" means output decimal integer.  
21.         System.out.println();  
22.         System.out.printf( "%o" , i); // "o" ​​means output octal integer.  
23.         System.out.println();  
24.         System.out.printf( "%x" , i); // "d" means output hexadecimal integer.  
25.         System.out.println();  
26.         System.out.printf( "%#x" , i); // "d" means output an integer with a hexadecimal flag.  
27.         System.out.println();  
28.         System.out.printf( "%s" , s); // "d" means output string.  
29.         System.out.println();  
30.         System.out.printf( "Output a float: %f, an integer: %d, a string: %s" , d, i, s);  
31.         // Multiple variables can be output, pay attention to the order.  
32.         System.out.println();  
33.         System.out.printf( "String: %2$s, hexadecimal number of %1$d: %1$#x" , i, s);  
34.         // "X$" represents the number of variables.  
35.     }  
36. }