the version of my predecessor will add $rep even if the string is shorter than max. fixed version:
<?php
function truncate($string, $max = 20, $rep = '')
{
if (strlen($string) <= ($max + strlen($rep)))
{
return $string;
}
$leave = $max - strlen ($rep);
return substr_replace($string, $rep, $leave);
}
?>
To preserve the filename extension you can call it like this:
truncate([filename], 30, '...' . end(explode('.', [filename])))
substr_replace
(PHP 4, PHP 5)
substr_replace — Replace text within a portion of a string
Description
substr_replace() replaces a copy of string delimited by the start and (optionally) length parameters with the string given in replacement .
Parameters
- string
-
The input string.
- replacement
-
The replacement string.
- start
-
If start is positive, the replacing will begin at the start 'th offset into string .
If start is negative, the replacing will begin at the start 'th character from the end of string .
- length
-
If given and is positive, it represents the length of the portion of string which is to be replaced. If it is negative, it represents the number of characters from the end of string at which to stop replacing. If it is not given, then it will default to strlen( string ); i.e. end the replacing at the end of string . Of course, if length is zero then this function will have the effect of inserting replacement into string at the given start offset.
Return Values
The result string is returned. If string is an array then array is returned.
Examples
Example #1 substr_replace() example
<?php
$var = 'ABCDEFGH:/MNRPQR/';
echo "Original: $var<hr />\n";
/* These two examples replace all of $var with 'bob'. */
echo substr_replace($var, 'bob', 0) . "<br />\n";
echo substr_replace($var, 'bob', 0, strlen($var)) . "<br />\n";
/* Insert 'bob' right at the beginning of $var. */
echo substr_replace($var, 'bob', 0, 0) . "<br />\n";
/* These next two replace 'MNRPQR' in $var with 'bob'. */
echo substr_replace($var, 'bob', 10, -1) . "<br />\n";
echo substr_replace($var, 'bob', -7, -1) . "<br />\n";
/* Delete 'MNRPQR' from $var. */
echo substr_replace($var, '', 10, -1) . "<br />\n";
?>
Notes
Note: This function is binary-safe.
substr_replace
28-Jul-2008 01:14
04-Jun-2008 05:42
PHP version of Java's removeCharAt() function:
<?php
function removeCharAt($str, $int){
return substr_replace($str,"",$int,1);
}
?>
23-Apr-2008 09:18
I recently ran across a situation where I need to strip a heavily nested html list such that only the top level was preserved. I started with a regular expression solution, but found that I kept matching the wrong closing ul with an outer opening ul.
This was my alternative solution, and it seems to work well:
<?php
function stripNestedLists($str)
{
$str2 = $str;
$lastStr = $str2;
do
{
// Find the first closing ul
$cul = strpos($str2, '</ul>');
$ul = 0;
$lastUL = 0;
do
{
// Find the next opening ul
$lastUL = $ul;
$ul = strpos($str2, '<ul', $ul+1);
}
while ($ul !== false && $ul < $cul);
$lastStr = $str2;
$str2 = substr_replace($str2, '', $lastUL, $cul-$lastUL+5);
$str2 = trim($str2);
}
while (strlen($str2) > 0);
return $lastStr;
}
?>
Hope this helps someone.
26-Mar-2008 07:53
I recently needed a routine that would remove the characters in one string from another, like the regex
<?php
$result = preg_replace("/[$chars]/", "", $string);
?>
and I needed it to be fast, and accept pretty much all input. The regex above won't work when strlen($chars) == 0. I came up with this, admittedly pretty horrible-looking code, that is quite fast:
<?php
function RemoveChars($string, $chars)
{
return isset($chars{0}) ? str_replace($chars{0}, "", strtr($string, $chars, str_pad($chars{0}, strlen($chars), $chars{0}))) : $string;
}
?>
According to my own measurements, the regex in ONLY faster for when strlen($chars) == 1; for longer strings, my routine is faster. What does it do? Let's say you want to remove the period, the comma and the exclamation mark from a string, like so:
$result = RemoveChars("Isn't this, like, totally neat..!?", ".?!");
The str_pad function creates a string equal in length to the string that contains the character to be removed, but consisting only of the first character of that string:
The input is ".,!"
The output is "..."
The strtr function translates all characters in the string-to-be-processed ("Isn't this...") that also occur in the input (".,!") to the characters in the same position in the output ("..."). In other words:
Isn't this, like, totally neat..!?
becomes
Isn't this. like. totally neat....
Finally, the first character from the input (".,!") which happens to be, again, the period, is removed from that string by the str_replace call:
Isn't this like totally neat?
The function needs to check is $chars has at least one character, or else the str_pad function will fail. If it's empty, then the unprocessed string is returned.
14-Feb-2008 10:07
Almost... In the previous note, change this :
<?php
function mb_substr_replace($string, $replacement, $start, $length=null, $encoding=null) {
if ($encoding == null) $encoding = mb_internal_encoding();
if($start < 0) $start = mb_strlen($string) + $start;
[...]
?>
13-Feb-2008 06:58
There is a mistake in the mb_substr_replace function below, when the $length parameter is given negative. Here is a working version.
<?php
//Check to see if it exists in case PHP has this function later
if (!function_exists("mb_substr_replace")){
//Same parameters as substr_replace with the extra encoding parameter.
function mb_substr_replace($string, $replacement, $start, $length=null, $encoding=null) {
if ($encoding == null) $encoding = mb_internal_encoding();
if ($length == null) {
return mb_substr($string, 0, $start, $encoding) . $replacement;
}
else {
if($length < 0) $length = mb_strlen($string, $encoding) - $start + $length;
return
mb_substr($string, 0, $start, $encoding) .
$replacement .
mb_substr($string, $start + $length, mb_strlen($string, $encoding), $encoding);
}
}
}
?>
07-Aug-2007 09:56
I like the truncate function below...however, I found a few issues. Particularly if you have content that may have any kind of punctuation in it (?, !, ?!?, --, ..., .., ;, etc.)
The older function would end up looking like "blah blah?..." or "blah blah,..." which doesn't look so nice to me...
Here's my fix. It removes all trailing punctuation (that you include in the $punctuation string below) and then adds an ellipse. So even if it has an ellipse with 3 dots, 2 dots, 4 dots, it'll be removed, then re-added.
<?php
function truncate($text,$numb,$etc = "...") {
$text = html_entity_decode($text, ENT_QUOTES);
if (strlen($text) > $numb) {
$text = substr($text, 0, $numb);
$text = substr($text,0,strrpos($text," "));
$punctuation = ".!?:;,-"; //punctuation you want removed
$text = (strspn(strrev($text), $punctuation)!=0)
?
substr($text, 0, -strspn(strrev($text), $punctuation))
:
$text;
$text = $text.$etc;
}
$text = htmlentities($text, ENT_QUOTES);
return $text;
}
?>
I also needed a sort of "middle" truncate. The above function truncates around the end, but if you want to truncate around the middle (ie "Hello this is a long string." --> "Hello this ... long string.") you can use this (requires the truncate function):
<?php
function mtruncate($text, $numb, $etc = " ... ") {
$first_part = truncate(truncate($text, strlen($text)/2, ""), $numb/2, "");
$second_part = truncate(strrev(truncate(strrev($text), strlen($text)/2, "")), $numb/2, "");
return $first_part.$etc.$second_part;
}
?>
07-Aug-2007 03:50
I've made a minor amendment to the function in the post below, to strip away the full stop (period) if the truncation occurs at the exact end of a sentence (the full stop spoils the ellipsis):
<?php
function truncate($text,$numb) {
$text = html_entity_decode($text, ENT_QUOTES);
if (strlen($text) > $numb) {
$text = substr($text, 0, $numb);
$text = substr($text,0,strrpos($text," "));
//This strips the full stop:
if ((substr($text, -1)) == ".") {
$text = substr($text,0,(strrpos($text,".")));
}
$etc = "...";
$text = $text.$etc;
}
$text = htmlentities($text, ENT_QUOTES);
return $text;
}
//Call function
truncate($text, 75);
21-Mar-2007 11:00
The two truncate functions provided below, have some major short comings.
1. They may cut a word in half
2. In case you are using htmlentities to get user input or are using wysiwyg editors to get user input, you can get truncated text like "he told C&eac..." instead of "he told Cécile" or "he told".
Here is what I use -
<?php
function truncate($text,$numb) {
// source: www.kigoobe.com, please keep this if you are using the function
$text = html_entity_decode($text, ENT_QUOTES);
if (strlen($text) > $numb) {
$text = substr($text, 0, $numb);
$text = substr($text,0,strrpos($text," "));
$etc = " ...";
$text = $text.$etc;
}
$text = htmlentities($text, ENT_QUOTES);
return $text;
}
// Now, to use this function, you can call that as -
truncate($text, 75);
?>
09-Dec-2005 12:33
I don't know if this function is multibyte safe but I've written a function that will do the same in multibyte mode.
<?php
//Check to see if it exists in case PHP has this function later
if (!function_exists("mb_substr_replace")){
//Same parameters as substr_replace with the extra encoding parameter.
function mb_substr_replace($string,$replacement,$start,$length=null,$encoding = null){
if ($encoding == null){
if ($length == null){
return mb_substr($string,0,$start).$replacement;
}
else{
return mb_substr($string,0,$start).$replacement.mb_substr($string,$start + $length);
}
}
else{
if ($length == null){
return mb_substr($string,0,$start,$encoding).$replacement;
}
else{
return mb_substr($string,0,$start,$encoding). $replacement. mb_substr($string,$start + $length,mb_strlen($string,$encoding),$encoding);
}
}
}
}
?>
06-Dec-2005 05:47
I created this because of the need to mask a credit-card number like **** **** **** 8862
string mask ( string str, int start [, int length] )
mask() masks a copy of str delimited by the start and (optionally) length parameters with asterisks (*) in place of non-whitespace characters
<?php
function mask ( $str, $start = 0, $length = null ) {
$mask = preg_replace ( "/\S/", "*", $str );
if ( is_null ( $length )) {
$mask = substr ( $mask, $start );
$str = substr_replace ( $str, $mask, $start );
} else {
$mask = substr ( $mask, $start, $length );
$str = substr_replace ( $str, $mask, $start, $length );
}
return $str;
}
?>
27-Aug-2005 08:48
I suggest changing the function suggested by Guru Evi slightly. I found that it doesn't work as written here.
Original:
function add_3dots($string,$repl,$start,$limit) {
if(strlen($string) > $limit) {
return substr_replace(strip_tags($string),$repl,$start,$limit);
} else {
return $string;
};
};
I suggest:
function add_3dots($string,$repl,$limit) {
if(strlen($string) > $limit) {
return substr_replace(strip_tags($string),$repl,$limit-strlen($repl));
} else {
return $string;
}
}
Usage:
$max_length=10;//the max number of characters you want to display
$too_long_string="BLAH BLAH BLAH BLAH BLAH etc.";//the string you want to shorten (if it's longer than the $limit)
$shorter_string=add_3_dots($too_long_string,"...",$max_length);
13-Jul-2005 09:44
If your string is not long enough to meet what you specify in start and length then the replacement string is added towards the end of the string.
I wanted to replace the end of the string with ... if the string was too long to display (for instance article preview on a website). The problem was that my string was sometimes not that long and it still added the replacement string. So I wrote a function to replace substr_replace in my website:
function add_3dots($string,$repl,$start,$limit) {
if(strlen($string) > $limit) {
return substr_replace(strip_tags($string),$repl,$start,$limit);
} else {
return $string;
};
};
I use strip_tags to strip out the HTML otherwise you might get a screwed up HTML (when a tags open in the string, but because you cut-off it doesn't)
22-Jan-2005 12:02
Actually, just a minor correction to tekrat at 2d dot com's post:
Change the code....
<?
if(strlen($substring) < 1){
$string = $rep;
}else{
$string = $substring;
}
?>
.... into....
<?
if(strlen($substring) >= 1){
$string = $substring;
}
?>
.... otherwise you'll end up with the elipses (...) for any null strings.
06-Jan-2005 05:55
Here's a slightly revised version of the truncation function above.
Theres isn't much of a reason to add in the $rep at the end of the original string is less then the truncation break point.
<?
function truncate($substring, $max = 50, $rep = '...') {
if(strlen($substring) < 1){
$string = $rep;
}else{
$string = $substring;
}
$leave = $max - strlen ($rep);
if(strlen($string) > $max){
return substr_replace($string, $rep, $leave);
}else{
return $string;
}
}
?>
10-Dec-2004 11:48
Using substr_replace() can be avoided by using substr() instead:
<?
$string = substr($string, 0, $position_needle).$replace.substr($string, $position_needle+$length_needle);
?>
This can be useful when you need to replace parts of multibyte strings like strings encoded with utf-8. There isn't a multibute variant for substr_replace(), but for php substr() there is mb_substr(). For more information on multibyte strings see http://nl3.php.net/manual/en/ref.mbstring.php
04-Aug-2004 11:28
A simple but useful 'pluralize' function using substr_replace:
function pluralize($noun) {
if ($noun{strlen($noun) -1} == "y")
$noun = substr_replace($noun, "ies", strlen($noun) -1);
else
$noun .= "s";
return $noun;
}
Handy when displaying dynamic text.
18-Jun-2004 01:34
Regarding "...", even the short functions are too long and complicated, and there's no need to use substr_replace. substr() works better and is way faster prior to 4.3.5 as the below poster stated.
function shorten( $str, $num = 100 ) {
if( strlen( $str ) > $num ) $str = substr( $str, 0, $num ) . "...";
return $str;
}
13-May-2004 09:55
The substr_replace() function is extremely slow in PHP versions prior to 4.3.5 and 5.0.0 so consider using an alternative before this time.
10-May-2004 11:25
The comment by geniusdex is a good one. Short, simple functions are the best. But if the string is not longer than the limit set, NOTHING is returned. Here is the function re-done to always return a string:
<?php
function dot($str, $len, $dots = "...") {
if (strlen($str) > $len) {
$dotlen = strlen($dots);
$str = substr_replace($str, $dots, $len - $dotlen);
}
return $str;
}
?>
23-Feb-2004 04:33
This is my version of making dotted strings:
<?php
function dot($str, $len, $dots = "...") {
if (strlen($str) > $len) {
$dotlen = strlen($dots);
substr_replace($str, $dots, $len - $dotlen);
}
}
?>
20-Jan-2004 08:05
I wrote a function that you can use for example in combination with a search script to cut off the articles that are too long.
<?php
function substr_index($text, $maxChars = 20, $splitter
= '...') {
$theReturn = $text;
$lastSpace = false;
if (strlen($text) > $maxChars) {
$theReturn = substr($text, 0, $maxChars - 1);
if (in_array(substr($text, $maxChars - 1, 1),
array(' ', '.', '!', '?'))) {
$theReturn .= substr($text, $maxChars, 1);
} else {
$theReturn = substr($theReturn, 0, $maxChars -
strlen($splitter));
$lastSpace = strrpos($theReturn, ' ');
if ($lastSpace !== false) {
$theReturn = substr($theReturn, 0, $lastSpace);
}
if (in_array(substr($theReturn, -1, 1), array(','))) {
$theReturn = substr($theReturn, 0, -1);
}
$theReturn .= $splitter;
}
}
return $theReturn;
}
?>
05-Nov-2003 01:40
The easiest way (I think) to add trailing dots after a string which in my case are too long is:
<?
function dots($num, $string) {
if (strlen($string) < $num) {
$string = substr_replace($string, '...', '-10', $num);
}
return $string;
}
Then on your page do something like:
<? echo dots("30" $row['title']); ?>
if the string is greater than the specific number it'll replace 3 dots.
I hope this helps =)
?>
06-Jul-2003 02:36
Here is a simple function to shorten a string and add an ellipsis
<?php
/**
* truncate() Simple function to shorten a string and add an ellipsis
*
* @param string $string Origonal string
* @param integer $max Maximum length
* @param string $rep Replace with... (Default = '' - No elipsis -)
* @return string
* @author David Duong
**/
function truncate ($string, $max = 50, $rep = '') {
$leave = $max - strlen ($rep);
return substr_replace($string, $rep, $leave);
}
echo truncate ('akfhslakdhglksjdgh', 10, '...');
// Returns akfhsla... (10 chrs)
?>
09-Oct-2002 12:01
To abbreviate links into '...' if they outreach a certain amount of space; use the preg_replace function instead.
For instance you grabbed the headlines of a news site for use on your own page and the lines are to long:
asuming the raw material is stored in $unedited;
$edited = preg_replace("/(>)([[:print:]]{52,})(<)/e", "'\\1'.substr_replace('\\2 ', '...', '48').'\\3'", $unedited);
echo $edited;
This will shorten strings longer than 52 characters into 51 characters, with the last being three dots...
13-Feb-2002 07:38
THE DOT DOT DOT ISSUE
PROBLEM:
You want to abbreviate a string.
E.g. You want "BritneySpears" to show as "BritneySpe...", being only the ten first characters followed by "..."
SOLUTION:
<?
$oRIGINAL = "BritneySpears";
$sHORTER = substr_replace($oRIGINAL, '...', 10);
echo ($sHORTER);
?>
This will result in BritneySpe...
If you would like to remove characters from the start or end of a string, try the substr() function.
For example, to remove the last three characters from a string:
$string = "To be or not to be.";
$string = substr ($string, 0, -3);
16-Apr-2001 09:16
Just to add to the examples, if replacement is longer than length, only the length number of chars are removed from string and all of replacement is put in its place, and therefor strlen($string) is inreased.
$var = 'ABCDEFGH:/MNRPQR/';
/* Should return ABCDEFGH:/testingRPQR/ */
echo substr_replace ($var, 'testing', 10, 2);
14-Mar-2001 03:29
[Editor's note: for a much simpler solution, use number_format()]
I had a situation in which I needed to add a comma to the third position of a number(the price of something).
<?php
$price = "12000";
$price = substr_replace ($price, ',', -3, 0)";
?>
the result would be 12,000
the -3 counts from right to left. a regular 3 would count from left to right
I hope this helps...
