str_rot13

str_repeat

Last updated: Fri, 27 Aug 2010

str_replace

(PHP 4, PHP 5)

str_replace — Replace all occurrences of the search string with the replacement string

Description

mixed str_replace ( mixed $search , mixed $replace , mixed $subject [, int &$count ] )

This function returns a string or an array with all occurrences of search in subject replaced with the given replace value.

If you don't need fancy replacing rules (like regular expressions), you should always use this function instead of ereg_replace() or preg_replace().

Parameters

If search and replace are arrays, then str_replace() takes a value from each array and uses them to do search and replace on subject. If replace has fewer values than search, then an empty string is used for the rest of replacement values. If search is an array and replace is a string, then this replacement string is used for every value of search. The converse would not make sense, though.

If search or replace are arrays, their elements are processed first to last.

search

The value being searched for, otherwise known as the needle. An array may be used to designate multiple needles.

replace

The replacement value that replaces found search values. An array may be used to designate multiple replacements.

subject

The string or array being searched and replaced on, otherwise known as the haystack.

If subject is an array, then the search and replace is performed with every entry of subject, and the return value is an array as well.

count

Note: If passed, this will hold the number of matched and replaced needles.

Return Values

This function returns a string or an array with the replaced values.

Changelog

Version	Description
5.0.0	The `count` parameter was added.
4.3.3	The behaviour of this function changed. In older versions a bug existed when using arrays as both `search` and `replace` parameters which caused empty `search` indexes to be skipped without advancing the internal pointer on the `replace` array. This has been corrected in PHP 4.3.3, any scripts which relied on this bug should remove empty search values prior to calling this function in order to mimic the original behavior.
4.0.5	Most parameters can now be an array.

Examples

Example #1 Basic str_replace() examples


<?php
// Provides: <body text='black'>
$bodytag = str_replace("%body%", "black", "<body text='%body%'>");

// Provides: Hll Wrld f PHP
$vowels = array("a", "e", "i", "o", "u", "A", "E", "I", "O", "U");
$onlyconsonants = str_replace($vowels, "", "Hello World of PHP");

// Provides: You should eat pizza, beer, and ice cream every day
$phrase  = "You should eat fruits, vegetables, and fiber every day.";
$healthy = array("fruits", "vegetables", "fiber");
$yummy   = array("pizza", "beer", "ice cream");

$newphrase = str_replace($healthy, $yummy, $phrase);

// Provides: 2
$str = str_replace("ll", "", "good golly miss molly!", $count);
echo $count;
?>

Example #2 Examples of potential str_replace() gotchas


<?php
// Order of replacement
$str     = "Line 1\nLine 2\rLine 3\r\nLine 4\n";
$order   = array("\r\n", "\n", "\r");
$replace = '<br />';

// Processes \r\n's first so they aren't converted twice.
$newstr = str_replace($order, $replace, $str);

// Outputs F because A is replaced with B, then B is replaced with C, and so on...
// Finally E is replaced with F, because of left to right replacements.
$search  = array('A', 'B', 'C', 'D', 'E');
$replace = array('B', 'C', 'D', 'E', 'F');
$subject = 'A';
echo str_replace($search, $replace, $subject);

// Outputs: apearpearle pear
// For the same reason mentioned above
$letters = array('a', 'p');
$fruit   = array('apple', 'pear');
$text    = 'a p';
$output  = str_replace($letters, $fruit, $text);
echo $output;
?>

Notes

Note: This function is binary-safe.

Caution

Replacement order gotcha

Because str_replace() replaces left to right, it might replace a previously inserted value when doing multiple replacements. See also the examples in this document.

Note:
This function is case-sensitive. Use str_ireplace() for case-insensitive replace.


I've found something interesting about the $count param:



As of 5.0.0 the last parameter (count) is passed by reference (it is optional). So 2 choices :

1)passed not by reference - it's limit

2)passed by reference : the var is is_null() - all occurences are replaced the number is returned in "count", otoh if the var !is_null() -> use as limit.



On version 5.3.0 the 4th parameter, count, does not work when not passed 

by reference.



http://bugs.php.net/bug.php?id=11457



Hope this help

apmuthu at usa dot net
19-Jun-2010 01:31


If we have a html template that contains placeholders in curly braces that need to be replaced in runtime, the following function will do it using str_replace:



<?php



function parse_template($filename, $data) {

// example template variables {a} and {bc}

// example $data array

// $data = Array("a" => 'one', "bc" => 'two');

    $q = file_get_contents($filename);

    foreach ($data as $key => $value) {

        $q = str_replace('{'.$key.'}', $value, $q);

    }

    return $q;

}



?>

cableray
11-Jun-2010 01:03


If you wish to get around the 'gotcha', you could do something like this:



<?php



$find=array('a', 'p', '^', '*');

$replace = array('^', '*', 'apple', 'pear');

str_replace($find, $replace, 'a p');



?>



The idea here is that you first replace the items you want with unique identifiers (that you are unlikely to find in the subject) and then search for those identifiers and then replace them.

christian dot reinecke at web dot de
14-May-2010 01:06


If you need to replace a string in another, but only once but still in all possible combinations (f.e. to replace "a" with "x" in "aba" to get array("xba", "abx")) you can use this function:

<?php

function getSingleReplaceCombinations($replace, $with, $inHaystack)

{

    $splits = explode($replace, $inHaystack);

    $result = array();

    for ($i = 1, $ix = count($splits); $i < $ix; ++$i) {

        $previous = array_slice($splits, 0, $i);

        $next     = array_slice($splits, $i);

        

        $combine  = array_pop($previous) . $with . array_shift($next);

        $result[] = implode($replace, array_merge($previous, array($combine), $next));

    }

    return $result;

}

var_dump(getSingleReplaceCombinations("a", "x", "aba")); // result as mentioned above

?>

It may not be the best in performance, but it works.

jbarnett at jmbelite dot com
26-Apr-2010 02:23


Might be worth mentioning that a SIMPLE way to accomplish Example 2 (potential gotchas) is to simply start your "replacements" in reverse.





So instead of starting from "A" and ending with "E":





<?php


$search  = array('A', 'B', 'C', 'D', 'E');


$replace = array('B', 'C', 'D', 'E', 'F');


// replaces A to B, B to C, C to D, D to E, E to F (makes them all F)


// start from "E" and end with "A":





$search  = array('E', 'D', 'C', 'B', 'A');


$replace = array('F', 'E', 'D', 'C', 'B');


// replaces E to F, D to E, C to D, B to C, A to B (prevents from


// multiple replacements of already replaced values)


?>





So basically start from the "end" and put the replacements in an order where the "replaced value" won't equal a value that exists later in the "search array".

pjcdawkins at googlemail dot com
23-Apr-2010 06:23


Here's a deep replace function allowing multi-dimensional arrays in $search, $replace and $subject. The keys and other structure of $subject are preserved.



<?php

// Auxiliary function:

function _replaceWithAnything($search,$replace,$subject){

  if(!is_array($search) || !is_array($replace)){

    $search=array($search);

    $replace=array($replace);

  }

  $match=array_search($subject,$search,true);

  if($match!==false && array_key_exists($match,$replace))

    $subject=$replace[$match];

  return $subject;

}



// Main function:

function deepReplace($search,$replace,$subject){

  if(!is_array($subject))

    return _replaceWithAnything($search,$replace,$subject);

  foreach($subject as &$val){

    if(is_array($val)){

      $val=deepReplace($search,$replace,$val);

      continue;

    }

    $val=_replaceWithAnything($search,$replace,$val);

  }

  return $subject;

}

?>

fleshgrinder at gmx dot at
16-Apr-2010 06:50


Fast function to replace new lines from a given string. This is interesting to replace all new lines from e. g. a text formatted in HTML retrieved from database and printing it without the unnecessary new lines. This results in slightly faster rendering in the Web browser.



<?php



/**

 * Replace all linebreaks with one whitespace.

 * 

 * @access public

 * @param string $string

 *   The text to be processed.

 * @return string

 *   The given text without any linebreaks.

 */

function replace_newline($string) {

  return (string)str_replace(array("\r", "\r\n", "\n"), '', $string);

}



?>

Wes Foster
17-Dec-2009 02:32


Feel free to optimize this using the while/for or anything else, but this is a bit of code that allows you to replace strings found in an associative array.





For example:


<?php


$replace = array(


'dog' => 'cat',


'apple' => 'orange'


'chevy' => 'ford'


);





$string = 'I like to eat an apple with my dog in my chevy';





echo str_replace_assoc($replace,$string);





// Echo: I like to eat an orange with my cat in my ford


?>





Here is the function:





<?php


function strReplaceAssoc(array $replace, $subject) {


   return str_replace(array_keys($replace), array_values($replace), $subject);    


}


?>





[Jun 1st, 2010 - EDIT BY thiago AT php DOT net: Function has been replaced with an updated version sent by ljelinek AT gmail DOT com]

jonathon at compwright dot com
12-Nov-2009 10:23


If you get a blank page when passing an object to str_replace() (relying on __toString() to convert the object to a string) then you may need to force string context using (string), like so:





<?php


private function _load_vars($vars, &$source = false) {


    if(!$source) $source =& $this->code;


        foreach((array)$vars as $key => $var) {


            $source = str_replace("{".$key."}", (string) $var, $source);


        }


    }


}


?>





I was running Ubuntu Server with PHP 5.2.6 and getting apache segfaults and mysterious blank pages when $var happened to be certain objects.

Chris
01-Nov-2009 09:22


Compress a string's internal spaces:

<?php

$str = ' This is    a    test   ';

$count = 1;

while($count)

    $str = str_replace('  ', ' ', $str, $count);

?>

Decko
15-Oct-2009 02:41


As mentioned earlier you should take the order into account when substituting multiple values.



However it is worth noticing that str_replace doesn't seem to re-read the string when doing single replacements. Take the following example.



<?php

  $s = '/a/a/';

  $s = str_replace('/a/', '/', $s);

?>



You would expect the following.



First replacement '/a/a/' -> '/a/'

Second replacement '/a/'->'/'



This is not the case, the actual result will be '/a/'.



To fix this, you will have to put str_replace in a while-loop.



<?php

  $s = '/a/a/';

  while(strpos($s, '/a/') !== false)

    $s = str_replace('/a/', '/', $s); //eventually $s will == '/'

?>

Alberto Lepe
15-Jun-2009 08:44


Be careful when replacing characters (or repeated patterns in the FROM and TO arrays):





For example:





<?php


$arrFrom = array("1","2","3","B");


$arrTo = array("A","B","C","D");


$word = "ZBB2";


echo str_replace($arrFrom, $arrTo, $word);


?>





I would expect as result: "ZDDB"


However, this return: "ZDDD"


(Because B = D according to our array)





To make this work, use "strtr" instead:





<?php


$arr = array("1" => "A","2" => "B","3" => "C","B" => "D");


$word = "ZBB2";


echo strtr($word,$arr);


?>





This returns: "ZDDB"

moz667 at gmail dot com
21-May-2009 10:49


<?php


/*


This is a function for made recursive str_replaces in an array


*/


function recursive_array_replace($find, $replace, &$data) {


    if (is_array($data)) {


        foreach ($data as $key => $value) {


            if (is_array($value)) {


                recursive_array_replace($find, $replace, $data[$key]);


            } else {


                $data[$key] = str_replace($find, $replace, $value);


            }


        }


    } else {


        $data = str_replace($find, $replace, $data);


    }


}





$a = array();


$a['a'] = "a";


$a['b']['a'] = "ba";


$a['b']['b'] = "bb";


$a['c'] = "c";


$a['d']['a'] = "da";


$a['d']['b'] = "db";


$a['d']['c'] = "dc";


$a['d']['d'] = "dd";





echo "Before Replaces";


print_r($a);





recursive_array_replace("a", "XXXX", $a);





echo "After Replaces";


print_r($a);


?>

michael dot moussa at gmail dot com
29-Jan-2009 07:38


As previous commentators mentioned, when $search contains values that occur earlier in $replace, str_replace will factor those previous replacements into the process rather than operating solely on the original string.  This may produce unexpected output.



Example:



<?php

$search = array('A', 'B', 'C', 'D', 'E');

$replace = array('B', 'C', 'D', 'E', 'F');

$subject = 'ABCDE';



echo str_replace($search, $replace, $subject); // output: 'FFFFFF'

?>



In the above code, the $search and $replace should replace each occurrence in the $subject with the next letter in the alphabet.  The expected output for this sample is 'BCDEF'; however, the actual output is 'FFFFF'.



To more clearly illustrate this, consider the following example:



<?php

$search = array('A', 'B', 'C', 'D', 'E');

$replace = array('B', 'C', 'D', 'E', 'F');

$subject = 'A';



echo str_replace($search, $replace, $subject); // output: 'F'

?>



Since 'A' is the only letter in the $search array that appears in $subject, one would expect the result to be 'B'; however, replacement number $n does *not* operate on $subject, it operates on $subject after the previous $n-1 replacements have been completed.



The following function utilizes array_combine and strtr to produce the expected output, and I believe it is the most efficient way to perform the desired string replacement without prior replacements affecting the final result.



<?php

/**

* When using str_replace(...), values that did not exist in the original string (but were put there by previous

* replacements) will be replaced continuously.  This string replacement function is designed replace the values

* in $search with those in $replace while not factoring in prior replacements.  Note that this function will

* always look for the longest possible match first and then work its way down to individual characters.

*

* The "o" in "stro_replace" represents "original", indicating that the function operates only on the original string.

*

* @param array $search list of strings or characters that need to be replaced

* @param array $replace list of strings or characters that will replace the corresponding values in $search

* @param string $subject the string on which this operation is being performed

*

* @return string $subject with all substrings in the $search array replaced by the values in the $replace array

*/

function stro_replace($search, $replace, $subject)

{

    return strtr( $subject, array_combine($search, $replace) );

}



$search = array('A', 'B', 'C', 'D', 'E');

$replace = array('B', 'C', 'D', 'E', 'F');

$subject = 'ABCDE';



echo stro_replace($search, $replace, $subject); // output: 'BCDEF'

?>



Some other examples:



<?php

$search = array(' ', '&');

$replace = array('&nbsp;', '&amp;');

$subject = 'Hello & goodbye!';



// We want to replace the spaces with &nbsp; and the ampersand with &amp;

echo str_replace($search, $replace, $subject); // output: "Hello&amp;nbsp&amp;&amp;nbspgoodbye!" - wrong!



echo stro_replace($search, $replace, $subject); // output: "Hello&nbsp;&amp;&nbsp;goodbye!" - correct!



/*

    Note:  Run the above code in the CLI or view source on your web browser - the replacement strings for stro_replace are HTML entities which the browser interprets.

*/

?>



<?php

$search = array('ERICA', 'AMERICA');

$replace = array('JON', 'PHP');

$subject = 'MIKE AND ERICA LIKE AMERICA';



// We want to replace the name "ERICA" with "JON" and the word "AMERICA" with "PHP"

echo str_replace($search, $replace, $subject); // output: "MIKE AND JON LIKE AMJON", which is not correct



echo stro_replace($search, $replace, $subject); // output: "MIKE AND JON LIKE PHP", which is correct

?>

nospam at nospam dot com
02-Dec-2008 03:55


Replacement for str_replace in which a multiarray of numerically keyed data can be properly evaluated with the given template without having a search for 11 be mistaken for two 1's next to each other





<?php





function data_template($input, $template) {


  if ($template) { // template string


    if ($split = str_split($template)) { // each char as array member


      foreach ($split as $char) { // each character


        if (is_numeric($char)) { // test for digit


          if ($s != 1) { // new digit sequence


            $i++;


            $s = 1;


          }


          $digits[$i] .= $char; // store digit


        } else { // not a digit


          if ($s != 2) { // new non-digit sequence


            $i++;


            $s = 2;


          }


          $strings[$i] .= $char; // store string


        }


      }


      if ($i && $input && is_array($input)) { // input data


        foreach ($input as $sub) { // each subarray


          if (is_array($sub)) {


            $out = ''; // reset output


            for ($j = 0; $j <= $i; $j++) { // each number/string member


              if ($number = $digits[$j]) { // number


                $out .= $sub[$number]; // add value from subarray to output


              } else { // string


                $out .= $strings[$j]; // add to output


              }


            }


            $a[] = $out;


          }


        }


        return $a;


      } // input


    } // split


  } // template


}





$input = array(array(1=>'yellow', 2=>'banana', 11=>'fruit'), array(1=>'green', 2=>'spinach', 11=>'vegetable'), array(1=>'pink', 2=>'salmon', 11=>'fish'));





print_r (data_template($input, '2: a 1, healthy 11'));





/*


Array


(


    [0] => banana: a yellow, healthy fruit


    [1] => spinach: a green, healthy vegetable


    [2] => salmon: a pink, healthy fish


)


*/





// str_replace would have wanted to output 'banana: a yellow, healthy yellowyellow





?>





Not sure if this will help anyone but I wrote it for my application and thought I would share just in case

nick at NOSPAM dot pitchinteractive dot com
06-Oct-2008 05:12


I tried max at efoxdesigns dot com solution for str_replace_once but it didn't work quite right so I came up with this solution (all params must be strings):



<?php

function str_replace_once($search, $replace, $subject) {

    $firstChar = strpos($subject, $search);

    if($firstChar !== false) {

        $beforeStr = substr($subject,0,$firstChar);

        $afterStr = substr($subject, $firstChar + strlen($search));

        return $beforeStr.$replace.$afterStr;

    } else {

        return $subject;

    }

}

?>

paolo A T doppioclick D O T com
05-Sep-2008 05:15


For PHP 4 < 4.4.5 and PHP 5 < 5.2.1 you may occur (like me) in this bug:



http://www.php-security.org/MOPB/MOPB-39-2007.html

troy at troyonline dot com
22-Jun-2008 11:18


Yet another deep replace function:



<?php

    function str_replace_deep( $search, $replace, $subject)

    {

        $subject = str_replace( $search, $replace, $subject);



        foreach ($subject as &$value)

            is_array( $value) and $value =str_replace_deep( $search, $replace, $value);

            

        return $subject;

    }

?>

David Gimeno i Ayuso (info at sima dot cat)
09-Aug-2007 01:22


With PHP 4.3.1, at least, str_replace works fine when working with single arrays but mess it all with two or more dimension arrays.



<?php

$subject = array("You should eat this","this","and this every day.");

$search  = "this";

$replace = "that";

$new     = str_replace($search, $replace, $subject);



print_r($new); // Array ( [0] => You should eat that [1] => that [2] => and that every day. )



echo "<hr />";



$subject = array(array("first", "You should eat this")

                ,array("second","this")

                ,array("third", "and this every day."));

$search  = "this";

$replace = "that";

$new     = str_replace($search, $replace, $subject);



print_r($new); // Array ( [0] => Array [1] => Array [2] => Array )



?>

tim at hysniu dot com
05-Jun-2007 12:27


I found that having UTF-8 strings in as argument didnt 

work for me using heavyraptors function. 

Adding UTF-8 as argument on htmlentities 

fixed the problem.



cheers, tim at hysniu.com



<?php

function replace_accents($str) {

  $str = htmlentities($str, ENT_COMPAT, "UTF-8");

  $str = preg_replace(

'/&([a-zA-Z])(uml|acute|grave|circ|tilde);/',

'$1',$str);

  return html_entity_decode($str);

}



?>

kole
25-Feb-2007 06:48


My input is MS Excel file but I want to save ‘,’,“,” as ',',",".



    $badchr        = array(

        "\xc2", // prefix 1

        "\x80", // prefix 2

        "\x98", // single quote opening

        "\x99", // single quote closing

        "\x8c", // double quote opening

        "\x9d"  // double quote closing

    );

        

    $goodchr    = array('', '', '\'', '\'', '"', '"');

        

    str_replace($badchr, $goodchr, $strFromExcelFile);



Works for me.

rlee0001 at sbcglobal dot net
16-Feb-2007 01:30


This is a more rigid alternative to spectrereturns at creaturestoke dot com's replace_different function:



<?php



        function str_replace_many ($search, $replacements, $subject) {

            $index = strlen($subject);

            $replacements = array_reverse($replacements);



            if (count($replacements) != substr_count($subject, $search)) {

                return FALSE;

            }



            foreach ($replacements as $replacement) {

                $index = strrpos(substr($subject, 0, $index), $search);

                $prefix = substr($subject, 0, $index);

                $suffix = substr($subject, $index + 1);

                $subject = $prefix . $replacement . $suffix;

            }



            return $subject;

        }

?>



This will return false if there are a different number of $replacements versus number of occurrences of $search in $subject. Additionally, $search much be exactly one character (if a string is provided, only the first character in the string will be used). Examples:



<?php

        echo str_replace_many('?',array('Jane','banana'),'? is eating a ?.');

?>



prints: "Jane is eating a banana."

15-Jan-2007 02:42


Before spending hours searching your application why it makes UTF-8 encoding into some malformed something with str_replace, make sure you save your PHP file in UTF-8 (NO BOM).



This was at least one of my problems.

matt wheaton
30-Mar-2006 08:40


As an effort to remove those Word copy and paste smart quotes, I've found that this works with UTF8 encoded strings (where $text in the following example is UTF8). Also the elipsis and em and en dashes are replaced.



There is an "invisible" character after the â€ for the right side double smart quote that doesn't seem to display here. It is chr(157).



<?php

  $find[] = 'â€œ';  // left side double smart quote

  $find[] = 'â€';  // right side double smart quote

  $find[] = 'â€˜';  // left side single smart quote

  $find[] = 'â€™';  // right side single smart quote

  $find[] = 'â€¦';  // elipsis

  $find[] = 'â€”';  // em dash

  $find[] = 'â€“';  // en dash



  $replace[] = '"';

  $replace[] = '"';

  $replace[] = "'";

  $replace[] = "'";

  $replace[] = "...";

  $replace[] = "-";

  $replace[] = "-";



  $text = str_replace($find, $replace, $text);

?>

David Gimeno i Ayuso (info at sima-pc dot com)
25-Aug-2003 07:12


Take care with order when using arrays in replacement.





<?php


$match=array("ONE","TWO","THREE");


$replace=array("TWO WORDS","MANY LETTERS","OTHER IDEAS");


$sample="ONE SAMPLE";


echo str_replace($match,$replace,$sample);


?>





It will show: "MANY LETTERS WORDS SAMPLE"





That is, after replacing "ONE" with "TWO WORDS", process follows with next array item and it changes "TWO" with "MANY LETTERS".

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