PHP intercepts a string and pads it with zeros str_pad function

Definition and usage
str_pad() function pads a string to the specified length.
Syntax
str_pad(string,length,pad_string,pad_type) Parameter Description
string Required. Specifies the string to be filled.
length required. Specifies the length of the new string. If the value is less than the length of the original string, no operation is performed.
pad_string optional. Specifies the string used for padding. The default is blank.
pad_type optional. Specifies the side of the padding string.
Possible values:
STR_PAD_BOTH - Pad to both ends of the string. If it's not an even number, the right side gets extra padding.
STR_PAD_LEFT - Pad to the left side of the string.
STR_PAD_RIGHT - Pad to the right side of the string. This is the default.
Example 1
$str = "http://www.jb51.net";
echo str_pad($str,30,".");
?>
Output:
http:// www.jb51.net.....
Example 2
$str = "http://www.jb51.net";
echo str_pad($str,30,".", STR_PAD_LEFT);
?>
Output:
.....http://www.jb51.net
Example 3
$str = "http://www.jb51.net ";
echo str_pad($str,30,".:",STR_PAD_BOTH);
?>
Output:
.:.:http://www.jb51.net.:.:

The above has introduced the str_pad function of PHP to intercept a string and fill it with zeros, including the relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.