How to remove line breaks (no characters!) from the string?

166
votes

This might appear to be a dupe, but rest assured it isn't - I have searched both SO as well as the rest of the web for an answer to my problem and ended up finding the same insufficient "solutions" over and over. Anyhow, here it goes:

I'm saving user input from a textarea to a MySQL database (within a WordPress environment, but that ought not to matter to this problem, I believe). It is later retrieved from the DB to be shown to Admins in the backend of the site. The problem occurs when users submit text with line breaks (i.e. hit the Enter key).

A sample string might look like this:

Dear friends, I just wanted so Hello. How are you guys? I'm fine, thanks!

Greetings,
Bill

There are no end of line characters ("\n", "\r", or the like) in the string.

I am using nl2br() on it to generate HTML output, but that's not enough. The result then is:

Dear friends, I just wanted so Hello. How are you guys? I'm fine, thanks!<br />
<br />
Greetings,<br />
Bill

Which, as far as I understand it, is the expected nl2br() result, as that inserts the tags and isn't supposed to replace the line-breaks in the first place?

However the format I need would be this:

Dear friends, I just wanted so Hello. How are you guys? I'm fine, thanks!<br /><br />Greetings,<br />Bill

If the string had EOL characters such as "\n" in it, I'd hit it with either str_replace() or preg_replace() and be done with it, but I have no clue what needle to feed either of those functions if there ain't no characters there in the first place.

I can manually access the relevant field in the DB, hit Backspace for every linebreak and what I later on want to do with the string works. So I know I need the above format.

11
phphtmlreplaceline-breaksnl2br
If the string looks like your first example, then how can you say it has no line break characters in it? It's got at least two: two in a row after "thanks!" – Ernest Friedman-Hill
Fair enuff @ErnestFriedman-Hill, you're obviously right - there's "something" there, it's just neither visible not anything I know. – Johannes Pille
I also can't see how is it possible to have new lines without line break characters. Can you use an hex editor to inspect the string - I am sure you will find the characters for new lines... – nettle

11 Answers

409
votes

You should be able to replace it with a preg that removes all newlines and carriage returns. The code is:

preg_replace( "/\r|\n/", "", $yourString );

Even though the \n characters are not appearing, if you are getting carriage returns there is an invisible character there. The preg replace should grab and fix those.

477
votes

Ben's solution is acceptable, but str_replace() is by far faster than preg_replace()

$buffer = str_replace(array("\r", "\n"), '', $buffer);

Using less CPU power, reduces the world carbon dioxide emissions.

16
votes
$str = "
Dear friends, I just wanted so Hello. How are you guys? I'm fine, thanks!<br />
<br />
Greetings,<br />
Bill";

echo str_replace(array("\n", "\r"), '', $str);  // echo $str in a single line
11
votes

It's because nl2br() doesn't remove new lines at all.

Returns string with <br /> or <br> inserted before all newlines (\r\n, \n\r, \n and \r).

Use str_replace instead:

$string = str_replace(array("\r\n", "\r", "\n"), "<br />", $string);
10
votes

str_replace(PHP_EOL, null, $str);

9
votes

You can also use PHP trim

This function returns a string with whitespace stripped from the beginning and end of str. Without the second parameter, trim() will strip these characters:

  • " " (ASCII 32 (0x20)), an ordinary space.
  • "\t" (ASCII 9 (0x09)), a tab.
  • "\n" (ASCII 10 (0x0A)), a new line (line feed).
  • "\r" (ASCII 13 (0x0D)), a carriage return.
  • "\0" (ASCII 0 (0x00)), the NUL-byte.
  • "\x0B" (ASCII 11 (0x0B)), a vertical tab.
7
votes

To work properly also on Windows I'd suggest to use

$buffer = str_replace(array("\r\n", "\r", "\n"), "", $buffer);

"\r\n" - for Windows, "\r" - for Mac and "\n" - for Linux

7
votes

Something a bit more functional (easy to use anywhere):

function strip_carriage_returns($string)
{
    return str_replace(array("\n\r", "\n", "\r"), '', $string);
}

Using PHP_EOL as the search replacement parameter is also a good idea! Kudos.

1
votes

Alternative built-in: trim()

trim — Strip whitespace (or other characters) from the beginning and end of a string
Description ¶
trim ( string $str [, string $character_mask = " \t\n\r\0\x0B" ] ) : string

This function returns a string with whitespace stripped from the beginning and end of str.
Without the second parameter, trim() will strip these characters:

    " " (ASCII 32 (0x20)), an ordinary space.
    "\t" (ASCII 9 (0x09)), a tab.
    "\n" (ASCII 10 (0x0A)), a new line (line feed).
    "\r" (ASCII 13 (0x0D)), a carriage return.
    "\0" (ASCII 0 (0x00)), the NUL-byte.
    "\x0B" (ASCII 11 (0x0B)), a vertical tab.

It's there to remove line breaks from different kinds of text files, but does not handle html.

1
votes

I use 3 lines to do this job, so consider $s as your "stuff"...

$s=str_replace(chr(10),'',$s);
$s=str_replace(chr(13),'',$s);
$s=str_replace("\r\n"),'',$s);
  • Legend:

chr(10)___a line feed

chr(13)___the return

\r\n______a new line

0
votes

You can use preg_replace in order to replace parts of a string matching a regular expression, like:

preg_replace("/\s+/","",$string);