Description
string 
number_format ( float number [, int decimals])
string 
number_format ( float number, int decimals, string dec_point, string thousands_sep)
     number_format() returns a formatted version of
     number.  This function accepts either one,
     two or four parameters (not three):
    
If only one parameter is given,
     number will be formatted without decimals,
     but with a comma (",") between every group of thousands.
    
     If two parameters are given, number will
     be formatted with decimals decimals with a
     dot (".") in front, and a comma (",") between every group of
     thousands.
    
     If all four parameters are given, number
     will be formatted with decimals decimals,
     dec_point instead of a dot (".") before
     the decimals and thousands_sep instead of
     a comma (",") between every group of thousands.
    
     Only the first character of thousands_sep
     is used.  For example, if you use foo as
     thousands_sep on the number
     1000, number_format() will
     return 1f000.
    
     
例子 1. number_format() Example 
       For instance, French notation usually use two decimals,
       comma (',') as decimal separator, and space (' ') as
       thousand separator. This is achieved with this line :
       
<?php
  $number = 1234.56;
  // english notation (default) $english_format_number = number_format($number); // 1,234
  // French notation $nombre_format_francais = number_format($number, 2, ',', ' '); // 1 234,56
  $number = 1234.5678;
  // english notation without thousands seperator $english_format_number = number_format($number, 2, '.', ''); // 1234.57
  ?>
 |  
  | 
    
     See also: sprintf(),
     printf() and sscanf().