Pad a string to a certain length with another string

说明

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.

参数

input: The input string.
pad_length: If the value of pad_length is negative or less than the length of the input string, no padding takes place.
pad_string: Note: The pad_string may be truncated if the required number of padding characters can't be evenly divided by the pad_string 's length.
pad_type: 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.

返回值

Returns the padded string.

范例

Example#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_"
?>