PHP built-in functions automatically complement digits or strings

Most of the time, we need to format the number. For example, if the number of digits is less than the first digit, we need to add 0. Php can be easily implemented, because PHP comes with related functions.

Most of the time, we need to format the number. For example, if the number of digits is less than the first digit, we need to add 0. Php can be easily implemented, because PHP comes with related functions.

Let's take a look at an example: the requirement is to generate 4-digit numbers. If it is not enough, add 0.

<? Php // generate 4-digit number, less than 0 $ var = sprintf ("% 04d", 2); echo $ var; // The result is 0002 echo date ('y _ m_d ', time ()). '_'. sprintf ('D', rand (0, 99);?>

Sprintf () function

Does it feel like a C language?

1. Syntax

Sprintf (format, arg1, arg2, arg ++)
Parameter description
Format is required. Conversion format.
Arg1 is required. Specifies the parameter inserted at the first % symbol in the format string.
Optional. Specifies the parameter inserted at the second % symbol in the format string.
Optional. Specifies the parameters inserted to the third, fourth, and other % symbols in the format string.

2. Description

The format parameter is the conversion format. It starts with the percent sign ("%") and ends with the conversion character. The following possible format values:

%-Percentage sign returned
% B-binary number
% C-Characters Based on ASCII values
% D-Signed decimal number
% E-resumable counting (for example, 1.5e + 3)
% U-Unsigned decimal number
% F-floating point number (local settings aware)
% F-floating point number (not local settings aware)
% O-octal values
% S-string
% X-hexadecimal (lowercase letter)
% X-hexadecimal (uppercase letters)
Parameters such as arg1, arg2, ++ are inserted to the percent sign (%) in the main string. This function is executed step by step. In the first % symbol, insert arg1, at the second % symbol, insert arg2, and so on.

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

3. Format number number_format ()

<? Php $ number = 1234.56; // english notation (default) $ english_format_number = number_format ($ number); // 1,235 // French notation $ nombre_format_francais = number_format ($ number, 2, ',', ''); // 1 1234.5678, 56 $ number =; // english notation without thousands seperator $ english_format_number = number_format ($ number, 2 ,'. ', ''); // 1234.57?>