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이 문서에서는 PHP 중국어 웹사이트 매뉴얼 풀어 주다
(PHP 4 >= 4.0.1, PHP 5)
str_pad — 使用另一个字符串填充字符串为指定长度
$input
, int $pad_length
[, string $pad_string
= " "
[, int $pad_type
= STR_PAD_RIGHT
]] )
该函数返回 input
被从左端、右端或者同时两端被填充到制定长度后的结果。如果可选的 pad_string
参数没有被指定,input
将被空格字符填充,否则它将被 pad_string
填充到指定长度。
input
输入字符串。
pad_length
如果 pad_length
的值是负数,小于或者等于输入字符串的长度,不会发生任何填充。
pad_string
Note:
如果填充字符的长度不能被
pad_string
整除,那么pad_string
可能会被缩短。
pad_type
可选的 pad_type
参数的可能值为 STR_PAD_RIGHT
, STR_PAD_LEFT
或 STR_PAD_BOTH
。如果没有指定 pad_type
,则假定它是 STR_PAD_RIGHT
。
返回填充后的字符串。
Example #1 str_pad() 范例
<?php
$input = "Alien" ;
echo str_pad ( $input , 10 ); // 输出 "Alien "
echo str_pad ( $input , 10 , "-=" , STR_PAD_LEFT ); // 输出 "-=-=-Alien"
echo str_pad ( $input , 10 , "_" , STR_PAD_BOTH ); // 输出 "__Alien___"
echo str_pad ( $input , 6 , "___" ); // 输出 "Alien_"
?>
[#1] Anonymous [2015-07-19 23:13:56]
For simple padding, you can use sprintf, which is faster:
see http://php.net/sprintf Example #5 "Specifying padding character"
[#2] mcinp [2015-01-29 16:04:54]
a different, more robust multibyte version of str_pad that works correctly only if $pad_string is non-multibyte string
function my_mb_str_pad($input, $pad_length, $pad_string=' ', $pad_type=STR_PAD_RIGHT,$encoding='UTF-8'){
$mb_diff=mb_strlen($str, $encoding)-strlen($string);
return str_pad($input,$pad_length+$mb_diff,$pad_string,$pad_type);
}
[#3] wes at nospamplsexample dot org [2014-11-28 18:29:56]
multibyte version:
<?php
function mb_str_pad($str, $pad_len, $pad_str = ' ', $dir = STR_PAD_RIGHT, $encoding = NULL)
{
$encoding = $encoding === NULL ? mb_internal_encoding() : $encoding;
$padBefore = $dir === STR_PAD_BOTH || $dir === STR_PAD_LEFT;
$padAfter = $dir === STR_PAD_BOTH || $dir === STR_PAD_RIGHT;
$pad_len -= mb_strlen($str, $encoding);
$targetLen = $padBefore && $padAfter ? $pad_len / 2 : $pad_len;
$strToRepeatLen = mb_strlen($pad_str, $encoding);
$repeatTimes = ceil($targetLen / $strToRepeatLen);
$repeatedString = str_repeat($pad_str, max(0, $repeatTimes)); // safe if used with valid utf-8 strings
$before = $padBefore ? mb_substr($repeatedString, 0, floor($targetLen), $encoding) : '';
$after = $padAfter ? mb_substr($repeatedString, 0, ceil($targetLen), $encoding) : '';
return $before . $str . $after;
}
?>
[#4] Marjune [2014-11-17 15:45:41]
since the default pad_type is STR_PAD_RIGHT. using STR_PAD_BOTH were always favor in the right pad if the required number of padding characters can't be evenly divided.
e.g
<?php
echo str_pad("input", 10, "pp", STR_PAD_BOTH ); // ppinputppp
echo str_pad("input", 6, "p", STR_PAD_BOTH ); // inputp
echo str_pad("input", 8, "p", STR_PAD_BOTH ); //pinputpp
?>
[#5] qeremy [atta] gmail [dotta] com [2013-01-20 01:44:44]
A proper unicode string padder;
<?php
mb_internal_encoding('utf-8'); // @important
function str_pad_unicode($str, $pad_len, $pad_str = ' ', $dir = STR_PAD_RIGHT) {
$str_len = mb_strlen($str);
$pad_str_len = mb_strlen($pad_str);
if (!$str_len && ($dir == STR_PAD_RIGHT || $dir == STR_PAD_LEFT)) {
$str_len = 1; // @debug
}
if (!$pad_len || !$pad_str_len || $pad_len <= $str_len) {
return $str;
}
$result = null;
$repeat = ceil($str_len - $pad_str_len + $pad_len);
if ($dir == STR_PAD_RIGHT) {
$result = $str . str_repeat($pad_str, $repeat);
$result = mb_substr($result, 0, $pad_len);
} else if ($dir == STR_PAD_LEFT) {
$result = str_repeat($pad_str, $repeat) . $str;
$result = mb_substr($result, -$pad_len);
} else if ($dir == STR_PAD_BOTH) {
$length = ($pad_len - $str_len) / 2;
$repeat = ceil($length / $pad_str_len);
$result = mb_substr(str_repeat($pad_str, $repeat), 0, floor($length))
. $str
. mb_substr(str_repeat($pad_str, $repeat), 0, ceil($length));
}
return $result;
}
?>
Test;
<?php
// needs ie. "test.php" file encoded in "utf-8 without bom"
$s = '...';
for ($i = 3; $i <= 1000; $i++) {
$s1 = str_pad($s, $i, 'AO', STR_PAD_BOTH); // can not inculde unicode char!!!
$s2 = str_pad_unicode($s, $i, '??', STR_PAD_BOTH);
$sl1 = strlen($s1);
$sl2 = mb_strlen($s2);
echo "len $sl1: $s1 \n";
echo "len $sl2: $s2 \n";
echo "\n";
if ($sl1 != $sl2) die("Fail!");
}
?>
Output;
len 3: ...
len 3: ...
len 4: ...A
len 4: ...?
len 5: A...A
len 5: ?...?
len 6: A...AO
len 6: ?...??
...
[#6] sergey [2011-10-12 02:45:42]
You can use trim functions for clearpad string:
ltrim("0001230", "0") -> 1230
rtrim("0123000", "0") -> 0123
trim("0012300") -> 123
[#7] gene at swipesy dot com [2011-09-24 21:18:15]
This is how I pad using :
str_replace(" ", " ", str_pad($foo, 10, " ", STR_PAD_LEFT))
Seems to work well using two tags for each character added, at least for my use. YMMV.
[#8] Kari "Haprog" Sderholm [2009-03-21 06:43:14]
Here's a quick and simple way to make an mb_str_pad function that works when you have correctly set your internal encoding.
I'm not sure how well this works in all possible scenarios but atleast it worked for me using UTF-8 as internal encoding and using this function on strings containing scandinavian characters "??????" that are double byte in UTF-8.
<?php
function mb_str_pad($input, $pad_length, $pad_string=' ', $pad_type=STR_PAD_RIGHT) {
$diff = strlen($input) - mb_strlen($input);
return str_pad($input, $pad_length+$diff, $pad_string, $pad_type);
}
?>
[#9] matrebatre [2008-10-16 11:28:10]
Here is a simple function to convert numbers into strings like this:
0 => 0000
1 => 0001
20 => 0020
432 => 0432
<?php
function number_pad($number,$n) {
return str_pad((int) $number,$n,"0",STR_PAD_LEFT);
}
?>
$n indicates how many characters you want.
[#10] bxi at apparoat dot nl [2008-03-20 06:17:20]
In case you want to pad 2 strings together with a character you can use:
<?php
function pad_between_strings($string1, $string2, $length, $char = " ") {
$fill_length = $length - ( strlen($string1) + strlen($string2) );
return $string1 . str_repeat($char, $fill_length) . $string2;
}
?>
[#11] Spudley [2007-07-18 08:47:54]
Warning: If your string includes non-ascii characters (eg the British pounds sign), str_pad() will treat these as two characters when calculating the padding.
So for example:
<?php
str_pad($currency_symbol.$showtottopay,12," ",STR_PAD_LEFT);
?>
will produce a different length string depending on whether $currency_symbol is pounds or dollars.
Hope this helps someone -- it caused me a lot of problems with misaligned columns in my invoices until I worked it out.
[#12] christian dot reinecke at web dot de [2007-04-01 10:43:56]
Fills the first argument (mostly a number, f.e. from a <select> loop to display a date or time) with zeroes.
<?php
function zerofill($mStretch, $iLength = 2)
{
$sPrintfString = '%0' . (int)$iLength . 's';
return sprintf($sPrintfString, $mStretch);
}
?>
sprintf() is indeed faster than str_pad.
[#13] Silvio Ginter (silvio dot ginter at gmx dot de) [2005-11-15 08:43:50]
Hello,
for anyone who needs this, I wrote this extension to str_pad. For details, just look at the comments.
<?php
$string = 'this is a test';
$oldLen = strlen($string);
$direction = STR_PAD_BOTH;
echo $string.'<br>';
echo str_const_len($string, 101, '#', $direction).'<br>';
echo $string.'<br>';
echo str_const_len($string, $oldLen, '#', $direction).'<br>';
echo $string.'<br><br>'."\n";
function str_const_len(&$str, $len, $char = ' ', $str_pad_const = STR_PAD_RIGHT) {
$origLen = strlen($str);
if (strlen($str) < $len) {
$str = str_pad($str, $len, $char, $str_pad_const);
}
else {
switch ($str_pad_const) {
case STR_PAD_LEFT:
$str = substr($str, (strlen($str) - $len), $len);
break;
case STR_PAD_BOTH:
$shorten = (int) ((strlen($str) - $len) / 2);
$str = substr($str, $shorten, $len);
break;
default:
$str = substr($str, 0, $len);
break;
}
}
return ($len - $origLen);
}
?>
[#14] private dot email at optusnet dot com dot au [2005-08-10 05:04:20]
I wrote these 3 functions that live in a library i include in every programme. I find them useful, and the syntax is easy.
<?php
$str = "test";
function str_pad_right ( $string , $padchar , $int ) {
$i = strlen ( $string ) + $int;
$str = str_pad ( $string , $i , $padchar , STR_PAD_RIGHT );
return $str;
}
function str_pad_left ( $string , $padchar , $int ) {
$i = strlen ( $string ) + $int;
$str = str_pad ( $string , $i , $padchar , STR_PAD_LEFT );
return $str;
}
function str_pad_both ( $string , $padchar , $int ) {
$i = strlen ( $string ) + ( $int * 2 );
$str = str_pad ( $string , $i , $padchar , STR_PAD_BOTH );
return $str;
}
echo str_pad_left ( $str , "-" , 3 ); // Produces: ---test
echo str_pad_right ( $str , "-" , 3 ); // Produces: test---
echo str_pad_both ( $str , "-" , 3 ); // Produces: ---test---
?>
Hope this can help someone!
[#15] zubfatal <root at it dot dk> [2005-03-27 21:28:08]
<?php
function str_pad_html($strInput = "", $intPadLength, $strPadString = " ", $intPadType = STR_PAD_RIGHT) {
if (strlen(trim(strip_tags($strInput))) < intval($intPadLength)) {
switch ($intPadType) {
// STR_PAD_LEFT
case 0:
$offsetLeft = intval($intPadLength - strlen(trim(strip_tags($strInput))));
$offsetRight = 0;
break;
// STR_PAD_RIGHT
case 1:
$offsetLeft = 0;
$offsetRight = intval($intPadLength - strlen(trim(strip_tags($strInput))));
break;
// STR_PAD_BOTH
case 2:
$offsetLeft = intval(($intPadLength - strlen(trim(strip_tags($strInput)))) / 2);
$offsetRight = round(($intPadLength - strlen(trim(strip_tags($strInput)))) / 2, 0);
break;
// STR_PAD_RIGHT
default:
$offsetLeft = 0;
$offsetRight = intval($intPadLength - strlen(trim(strip_tags($strInput))));
break;
}
$strPadded = str_repeat($strPadString, $offsetLeft) . $strInput . str_repeat($strPadString, $offsetRight);
unset($strInput, $offsetLeft, $offsetRight);
return $strPadded;
}
else {
return $strInput;
}
}
?>
[#16] bob [at] bobarmadillo [dot] com [2002-12-03 09:22:49]
In a lot of cases you're better off using str_repeat if you want to use something like - it repeats the entire string.
Using str_repeat, I wrote a full string pad function that should closely mimic str_pad in every other way:
<?php
function full_str_pad($input, $pad_length, $pad_string = '', $pad_type = 0) {
$str = '';
$length = $pad_length - strlen($input);
if ($length > 0) { // str_repeat doesn't like negatives
if ($pad_type == STR_PAD_RIGHT) { // STR_PAD_RIGHT == 1
$str = $input.str_repeat($pad_string, $length);
} elseif ($pad_type == STR_PAD_BOTH) { // STR_PAD_BOTH == 2
$str = str_repeat($pad_string, floor($length/2));
$str .= $input;
$str .= str_repeat($pad_string, ceil($length/2));
} else { // defaults to STR_PAD_LEFT == 0
$str = str_repeat($pad_string, $length).$input;
}
} else { // if $length is negative or zero we don't need to do anything
$str = $input;
}
return $str;
}
$pad_me = "Test String";
echo '|'.full_str_pad($pad_me, 20, ' ')."|\n";
echo '|'.full_str_pad($pad_me, 20, ' ', STR_PAD_RIGHT)."|\n";
echo '|'.full_str_pad($pad_me, 20, ' ', STR_PAD_BOTH)."|\n";
?>
[#17] Fahad dot Gilani at anu dot edu dot au [2002-12-02 02:22:43]
Basically, *all* of you guys have a 'long' way of padding text with html tags (which includes ) You dont even have to do a str_replace... try the following code and this will work with ANY html tag there is out there and you don't have to worry about tag character lengths so on and so forth:
<?php
$text = "This is pretty interesting!";
$pad_string = " ";
//Pad text on both sides
$text = str_pad($text, strlen($text)+(20*strlen($pad_string)), $pad_string, STR_PAD_BOTH);
print $text." Dont you think?";
?>
Will produce:
This is pretty interesting! Dont you think?
Cheers,
Fahad
[#18] mreilly at NOSPAM dot mac dot com [2002-08-20 11:23:34]
When provided with a string of characters as the pad value, str_pad uses all the characters as fill, and can leave partial strings. (eg. If the pad value is 'ABC' and it needs 5 characters to pad with, it outputs 'ABCAB'.) This is a problem when you want to pad with non-breaking spaces, the code for which is 6 characters long.
This can be resolved by first padding the string with a single character that won't be found in the strings such as * then doing a str_replace of * with .
[#19] pestilenc at hotmail dot com [2002-06-06 04:26:44]
For me this worked.
$string = 'help';
#First, str_pad() with unique character.
$string = str_pad($string, 10, "*", STR_PAD_BOTH);
#$string = '***help***';
#Second, str_replace with ' '
$string = str_replace("*", " ", $string);