It's important to remember that this function does NOT replace newlines with <br> tags. Rather, it inserts a <br> tag before each newline, but it still preserves the newlines themselves! This caused problems for me regarding a function I was writing -- I forgot the newlines were still being preserved.
If you don't want newlines, do:
<?php
$Result = str_replace( "\n", '<br />', $Text );
?>
nl2br
(PHP 4, PHP 5, PHP 7, PHP 8)
nl2br — 改行文字の前に HTML の改行タグを挿入する
説明
string に含まれるすべての改行文字 (\r\n、
\n\r、\n および \r)
の前に <br /> あるいは <br> を挿入して返します。
パラメータ
-
string -
入力文字列。
-
use_xhtml -
XHTML 準拠の改行を使うか否か。
戻り値
変更後の文字列を返します。
例
例1 nl2br() の使用法
<?php
echo nl2br("foo isn't\n bar");
?>上の例の出力は以下となります。
foo isn't<br /> bar
例2 use_xhtml パラメータを使い、妥当な HTML 形式のマークアップを生成する
<?php
echo nl2br("Welcome\r\nThis is my HTML document", false);
?>上の例の出力は以下となります。
Welcome<br> This is my HTML document
例3 さまざまな改行文字
<?php
$string = "This\r\nis\n\ra\nstring\r";
echo nl2br($string);
?>上の例の出力は以下となります。
This<br /> is<br /> a<br /> string<br />
参考
- htmlspecialchars() - 特殊文字を HTML エンティティに変換する
- htmlentities() - 適用可能な文字を全て HTML エンティティに変換する
- wordwrap() - 指定した文字数で文字列を分割する
- str_replace() - 検索文字列に一致したすべての文字列を置換する
add a note
User Contributed Notes 17 notes
CGameProgrammer at gmail dot com ¶
19 years ago
ngkongs at gmail dot com ¶
17 years ago
to replace all linebreaks to <br />
the best solution (IMO) is:
<?php
function nl2br2($string) {
$string = str_replace(array("\r\n", "\r", "\n"), "<br />", $string);
return $string;
}
?>
because each OS have different ASCII chars for linebreak:
windows = \r\n
unix = \n
mac = \r
works perfect for me
N/A ¶
16 years ago
Here's a more simple one:
<?php
/**
* Convert BR tags to nl
*
* @param string The string to convert
* @return string The converted string
*/
function br2nl($string)
{
return preg_replace('/\<br(\s*)?\/?\>/i', "\n", $string);
}
?>
Enjoy
aabaev ¶
6 years ago
double quotes !== single quotes
php > echo nl2br('\r\n');
\r\n
php > echo nl2br("\r\n");
<br />
fquffio at live dot it ¶
10 years ago
Starting from PHP 4.3.10 and PHP 5.0.2, this should be the most correct way to replace <br /> and <br> tags with newlines and carriage returns.
<?php
/**
* Convert BR tags to newlines and carriage returns.
*
* @param string The string to convert
* @return string The converted string
*/
function br2nl ( $string )
{
return preg_replace('/\<br(\s*)?\/?\>/i', PHP_EOL, $string);
}
?>
(Please note this is a minor edit of this function: http://php.net/nl2br#86678 )
You might also want to be "platform specific", and therefore this function might be of some help:
<?php
/**
* Convert BR tags to newlines and carriage returns.
*
* @param string The string to convert
* @param string The string to use as line separator
* @return string The converted string
*/
function br2nl ( $string, $separator = PHP_EOL )
{
$separator = in_array($separator, array("\n", "\r", "\r\n", "\n\r", chr(30), chr(155), PHP_EOL)) ? $separator : PHP_EOL; // Checks if provided $separator is valid.
return preg_replace('/\<br(\s*)?\/?\>/i', $separator, $string);
}
?>
Anders Norrbring ¶
18 years ago
Seeing all these suggestions on a br2nl function, I can also see that neither would work with a sloppy written html line break.. Users can't be trusted to write good code, we know that, and mixing case isn't too uncommon.
I think this little snippet would do most tricks, both XHTML style and HTML, even mixed case like <Br> <bR /> and even <br > or <br />.
<?php
function br2nl($text)
{
return preg_replace('/<br\\s*?\/??>/i', '', $text);
}
?>
chad at nobodyfamous dot ca ¶
7 years ago
I just spent a whole day trying to figure out why my textarea $_POST was not getting <br /> tags added by nl2br(). So for others
<?php filter_input(INPUT_POST, 'text', FILTER_SANITIZE_SPECIAL_CHARS); ?> returns newlines as and so nl2br will miss them.
rather use <?php filter_input(INPUT_POST, 'text', FILTER_SANITIZE_STRING); ?> and newlines will remain intact so nl2br will pick them up.
Justinas M. ¶
8 years ago
This is example with "\R" regex token which matches any unicode newline character.
"u" flag treate strings as UTF-16. Which is optional, depending on your use case.
<?php
public function nl2br($string)
{
return preg_replace('/\R/u', '<br/>', $string);
}
?>
NOTE:
preg_replace versions are much slower than using str_replace version or built-in nl2br.
Check out pcre.backtrack_limit php.ini setting for information about PCRE limit. It's good to know.
Some PHP7 benchmarks:
<?php
// nl2br()
function nl2br_str($string) {
return str_replace(["\r\n", "\r", "\n"], '<br/>', $string);
}
function nl2br_preg_R($string)
{
return preg_replace('/\R/u', '<br/>', $string);
}
function nl2br_preg_rnnr($string)
{
return preg_replace('/(\r\n|\n|\r)/', '<br/>', $string);
}
?>
# nl2br
## Time: 0.02895712852478 s
# nl2br_str
## Time: 0.027923107147217 s
# nl2br_preg_R
## Time: 0.13350105285645 s
# nl2br_preg_rnnr
## Time: 0.14213299751282 s
Collette ¶
4 years ago
Let's say a form text field does contain:
test line number 1
test line number 2
To remove all the line breaks and split the input into an array:
$input_from_text_field = preg_replace('#[\r\n]#','',nl2br($input_from_text_field,false));
$lines = explode("<br>",$input_from_text_field);
$lines will now be an array where $lines[0] = "test line number 1" and so on.
leo dot mauro dot desenv at gmail dot com ¶
9 years ago
I test empirically this function nl2br and nl2br2 (create by ngkongs at gmail dot com).
Both work nice with different ASCII chars for linebreak, but the function nl2br2 is faster than nl2br.
nl2br2 ~ 0.0000309944153 s
nl2br ~ 0.0011141300201 s
The function nl2br2:
<?php
function nl2br2($string) {
$string = str_replace(array("\r\n", "\r", "\n"), "<br />", $string);
return $string;
}
?>
gautier dot michelin at gmail dot com ¶
4 years ago
This is a simple trick to transform newlines to paragraph a $string :
<?php
$string_with_paragraphs = "<p>".implode("</p><p>", explode("\n", $string))."</p>";
?>
By exploding on new lines & adding end & begin for p, it's easy to concat with <p>.
You can bring it to a function :
<?php
function nl2p($string) {
return $string_with_paragraphs = "<p>".implode("</p><p>", explode("\n", $string))."</p>";
}
?>
blacknine313 at gmail dot com ¶
16 years ago
After a recent post at the forums on Dev Shed, I noticed that it isn't mentioned, so I will mention it.
nl2br returns pure HTML, so it should be after PHP anti-HTML functions ( such as strip_tags and htmlspecialchars ).
buzanits at gmail dot com ¶
7 years ago
If you write code that is to run in browser AND on the shell, this function could be useful. It uses PHP_EOL or <br /> depending on the platform it runs:
<?php
function nl($string) {
if(isset($_SERVER['SHELL'])) return preg_replace('/\<br(\s*)?\/?\>/i', PHP_EOL, $string);
return nl2br($string);
}
print nl("One\nTwo<br>Three\r\nFour<br />Five
Six" . PHP_EOL);
?>
j dot mons54 at gmail dot com ¶
12 years ago
for bbcode :
<?php
$message = nl2br(preg_replace('#(\\]{1})(\\s?)\\n#Usi', ']', stripslashes($message)));
?>
darenschwenke at yahoo dot com ¶
10 years ago
This one works with br tags having attributes, in any case,
closed or not closed, and does not double linefeeds
<?php
/**
* convert br tags to nl
*
* @param string The string to convert
* @return string The converted string
*/
function br2nl($string)
{
return preg_replace("/<br[^>]*>\s*\r*\n*/is", "\n", $string);
}
?>
I combine this with strip_tags() for dead simple "contenteditable" fields allowing only text and linefeeds.
Patrik ¶
2 years ago
Consider using CSS's `white-space: pre-line;` instead, it does the same thing as nl2br().
hyponiq at gmail dot com ¶
17 years ago
On the contrary, <b>mark at dreamjunky.comno-spam</b>, this function is rightfully named. Allow me to explain. Although it does re-add the line break, it does so in an attempt to stay standards-compliant with the W3C recommendations for code format.
According to said recommendations, a new line character must follow a line break tag. In this situation, the new line is not removed, but a break tag is added for proper browser display where a paragraph isn't necessary or wanted.
