str_pad

(PHP 4 >= 4.0.1, PHP 5)

str_pad --  Pad a string to a certain length with another string

Description

string str_pad ( string input, int pad_length [, string pad_string [, int pad_type]])

This functions returns the input string padded on the left, the right, or both sides to the specified padding length. If the optional argument pad_string is not supplied, the input is padded with spaces, otherwise it is padded with characters from pad_string up to the limit.

Optional argument pad_type can be STR_PAD_RIGHT, STR_PAD_LEFT, or STR_PAD_BOTH. If pad_type is not specified it is assumed to be STR_PAD_RIGHT.

If the value of pad_length is negative or less than the length of the input string, no padding takes place.

例子 1. str_pad() example

<?php
$input
= "Alien";
echo
str_pad($input, 10);                      // produces "Alien     "
echo str_pad($input, 10, "-=", STR_PAD_LEFT);  // produces "-=-=-Alien"
echo str_pad($input, 10, "_", STR_PAD_BOTH);   // produces "__Alien___"
echo str_pad($input, 6 , "___");               // produces "Alien_"
?>

注: The pad_string may be truncated if the required number of padding characters can't be evenly divided by the pad_string's length.