PHP Conference Nagoya 2025

rtrim

(PHP 4, PHP 5, PHP 7, PHP 8)

rtrim Rimuove gli spazi (ed altri caratteri) dalla fine della stringa

Descrizione

rtrim(string $str, string $charlist = ?): string

Nota: Il secondo parametro è stato aggiunto nella versione 4.1.0 di PHP.

Questa funzione restituisce la stringa str a cui sono stati rimossi gli spazi finali. Senza la specifica del secondo parametro rtrim() rimuoverà i seguenti caratteri:

  • " " (ASCII 32 (0x20)), spazio ordinario.
  • "\t" (ASCII 9 (0x09)), tab.
  • "\n" (ASCII 10 (0x0A)), newline (line feed).
  • "\r" (ASCII 13 (0x0D)), carriage return.
  • "\0" (ASCII 0 (0x00)), il byte NUL.
  • "\x0B" (ASCII 11 (0x0B)), il tab verticale.

Si può anche specificare i caratteri che si desidera rimuovere, indicandoli nel parametro charlist. Quest'ultimo è costituito da un semplice elenco di caratteri da rimuovere. Con .. si può specificare un range di caratteri.

Example #1 Esempio di uso di rtrim()

<?php

$text
= "\t\tThese are a few words :) ... ";
$trimmed = rtrim($text);
// $trimmed = "\t\tThese are a few words :) ..."
$trimmed = rtrim($text, " \t.");
// $trimmed = "\t\tThese are a few words :)"
$clean = rtrim($binary, "\x00..\x1F");
// rimuove i caratteri di controllo ASCII dalla fine di $binary
// (from 0 to 31 inclusive)

?>

Vedere anche trim() e ltrim().

add a note

User Contributed Notes 7 notes

up
44
pinkgothic at gmail dot com
14 years ago
I have an obsessive love for php's array functions given how extremely easy they've made complex string handling for me in various situations... so, have another string-rtrim() variant:

<?php

function strrtrim($message, $strip) {
// break message apart by strip string
$lines = explode($strip, $message);
$last = '';
// pop off empty strings at the end
do {
$last = array_pop($lines);
} while (empty(
$last) && (count($lines)));
// re-assemble what remains
return implode($strip, array_merge($lines, array($last)));
}

?>

Astonishingly, something I didn't expect, but: It completely compares to harmor's rstrtrim below, execution time wise. o_o Whee!
up
30
gbelanger at exosecurity dot com
18 years ago
True, the Perl chomp() will only trim newline characters. There is, however, the Perl chop() function which is pretty much identical to the PHP rtrim()

---

Here's a quick way to recursively trim every element of an array, useful after the file() function :

<?php
# Reads /etc/passwd file an trims newlines on each entry
$aFileContent = file("/etc/passwd");
foreach (
$aFileContent as $sKey => $sValue) {
$aFileContent[$sKey] = rtrim($sValue);
}

print_r($aFileContent);
?>
up
26
todd at magnifisites dot com
21 years ago
This shows how rtrim works when using the optional charlist parameter:
rtrim reads a character, one at a time, from the optional charlist parameter and compares it to the end of the str string. If the characters match, it trims it off and starts over again, looking at the "new" last character in the str string and compares it to the first character in the charlist again. If the characters do not match, it moves to the next character in the charlist parameter comparing once again. It continues until the charlist parameter has been completely processed, one at a time, and the str string no longer contains any matches. The newly "rtrimmed" string is returned.
<?php
// Example 1:
rtrim('This is a short short sentence', 'short sentence');
// returns 'This is a'
// If you were expecting the result to be 'This is a short ',
// then you're wrong; the exact string, 'short sentence',
// isn't matched. Remember, character-by-character comparison!
// Example 2:
rtrim('This is a short short sentence', 'cents');
// returns 'This is a short short '
?>
up
21
Unimagined at UnaimaginedDesigns dot Com
19 years ago
I needed a way to trim all white space and then a few chosen strings from the end of a string. So I wrote this class to reuse when stuff needs to be trimmed.

<?php

class cleaner {

function
cleaner ($cuts,$pinfo) {
$ucut = "0";
$lcut = "0";
while (
$cuts[$ucut]) {
$lcut++;
$ucut++;
}
$lcut = $lcut - 1;
$ucut = "0";
$rcut = "0";
$wiy = "start";

while (
$wiy) {

if (
$so) {
$ucut = "0";
$rcut = "0";
unset(
$so);
}

if (!
$cuts[$ucut]) {
$so = "restart";
} else {
$pinfo = rtrim($pinfo);
$bpinfol = strlen($pinfo);
$tcut = $cuts[$ucut];
$pinfo = rtrim($pinfo,"$tcut");
$pinfol = strlen($pinfo);

if (
$bpinfol == $pinfol) {
$rcut++;
if (
$rcut == $lcut) {
unset(
$wiy);
}
$ucut++;
} else {
$so = "restart";
}
}
}

$this->cleaner = $pinfo;
}

}

$pinfo = "Well... I'm really bored...<br /><br>&nbsp; \n\t&nbsp;<br><br /><br>&nbsp; \r\r&nbsp;<br>\r<br /><br>\r&nbsp; &nbsp;\n<br> <br />\t";

$cuts = array('\n','\r','\t',' ',' ','&nbsp;','<br />','<br>','<br/>');

$pinfo = new cleaner($cuts,$pinfo);
$pinfo = $pinfo->cleaner;

print
$pinfo;

?>

That class will take any string that you put in the $cust array and remove it from the end of the $pinfo string. It's useful for cleaning up comments, articles, or mail that users post to your site, making it so there's no extra blank space or blank lines.
up
16
pinkgothic at gmail dot com
11 years ago
On the recurring subject of string-stripping instead of character-stripping rtrim() implementations... the simplest (with a caveat) is probably the basename() function. It has a second parameter that functions as a right-trim using whole strings:

<?php

echo basename('MooFoo', 'Foo');

?>

...outputs 'Moo'.

Since it also strips anything that looks like a directory, it's not quite identical with hacking a string off the end:

<?php

echo basename('Zoo/MooFoo', 'Foo');

?>

...still outputs 'Moo'.

But sometimes it gets the job done.
up
5
harmor
16 years ago
I'm sure there's a better way to strip strings from the end of strings.

<?php
/**
* Strip a string from the end of a string
*
* @param string $str the input string
* @param string $remove OPTIONAL string to remove
*
* @return string the modified string
*/
function rstrtrim($str, $remove=null)
{
$str = (string)$str;
$remove = (string)$remove;

if(empty(
$remove))
{
return
rtrim($str);
}

$len = strlen($remove);
$offset = strlen($str)-$len;
while(
$offset > 0 && $offset == strpos($str, $remove, $offset))
{
$str = substr($str, 0, $offset);
$offset = strlen($str)-$len;
}

return
rtrim($str);

}
//End of function rstrtrim($str, $remove=null)

echo rstrtrim('Hello World!!!', '!') .'<br />'; //"Hello World"
echo rstrtrim('Hello World!!!', '!!') .'<br />'; //"Hello World!"
echo rstrtrim('Hello World!!!', '!!!') .'<br />'; //"Hello World"
echo rstrtrim('Hello World!!!', '!!!!').'<br />'; //"Hello World!!!"
?>
up
-2
HW
21 years ago
<?php
$text
= "This string contains some unwanted characters on the end.";
$text1 = rtrim($text, 'a..z');
$text1 = rtrim($text1, '.');
echo
$text1; // only the '.' is trimmed.
$text2 = rtrim($text, 'a..z.');
echo
$text2; // The whole last word is trimmed.
?>
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