Hướng dẫn nl2br wordpress

[PHP 4, PHP 5, PHP 7, PHP 8]

nl2br — Inserts HTML line breaks before all newlines in a string

Description

nl2br[string $string, bool $use_xhtml = true]: string

Parameters

The input string.

Whether to use XHTML compatible line breaks or not.

Return Values

Returns the altered string.

Examples

Example #1 Using nl2br[]

Justinas M. ¶

6 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.



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:


# nl2br
## Time: 0.02895712852478 s

# nl2br_str
## Time: 0.027923107147217 s

# nl2br_preg_R
## Time: 0.13350105285645 s

leo dot mauro dot desenv at gmail dot com ¶

7 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:


Collette ¶

2 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]];
$lines = explode["
",$input_from_text_field];

$lines will now be an array where $lines[0] = "test line number 1" and so on.

chad at nobodyfamous dot ca ¶

5 years ago

I just spent a whole day trying to figure out why my textarea $_POST was not getting
tags added by nl2br[].  So for others

returns newlines as  and so nl2br will miss them.

rather use and newlines will remain intact so nl2br will pick them up.

buzanits at gmail dot com ¶

4 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
depending on the platform it runs:

blacknine313 at gmail dot com ¶

14 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 ].

darenschwenke at yahoo dot com ¶

8 years ago

This one works with br tags having attributes, in any case,
closed or  not closed, and does not double linefeeds



I combine this with strip_tags[] for dead simple "contenteditable" fields allowing only text and linefeeds.

j dot mons54 at gmail dot com ¶

10 years ago

for bbcode :

hyponiq at gmail dot com ¶

15 years ago

On the contrary, mark at dreamjunky.comno-spam, 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.