How to format numbers in php and add 0 in front of insufficient digits

Example of php formatting numbers.

<?php   
 $var=sprintf("%04d", 2);//生成4位数，不足前面补0   
 echo $var;//结果为0002   
?>

1. String sprintf() function Grammar

sprintf(format,arg1,arg2,arg++)

The parameter format is the format of the conversion, starting with the percent sign ("%") and ending with the conversion character. The following possible format values ​​are: %% - returns the percent symbol %b - binary number %c - character according to ASCII value %d - signed decimal number %e - Continuous counting method (e.g. 1.5e+3) %u - unsigned decimal number %f - floating point number (local settings aware) %F - floating point number (not local settings aware) %o - octal number %s - string %x - hexadecimal number (lowercase letters) %X - Hexadecimal number (capital letters)

arg1, arg2, ++, etc. are inserted into the main string at the percent sign (%) symbol. This function is executed step by step. At the first % sign, arg1 is inserted, at the second % sign, arg2, and so on. Example:

<?php   
 $number = 123;   
 $txt = sprintf("%f",$number);   
 echo $txt;   
?> 

2. Format number function number_format() Example:

<?php
//number_format 格式化数字
$number = 1234.56;

// english notation (default)
$english_format_number = number_format($number);
// 1,235

// 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

//by http://bbs.it-home.org
?>