str_replace

(PHP 4, PHP 5, PHP 7)

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 preg_replace().

Parameters

If search and replace are arrays, then str_replace() takes a value from each array and uses them to 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

If passed, this will be set to the number of replacements performed.

Return Values

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

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.

User Contributed Notes

nikolaz dot tang at hotmail dot com

5 years ago


A faster way to replace the strings in multidimensional array is to json_encode() it, do the str_replace() and then json_decode() it, like this:



<?php

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

     return json_decode(str_replace($search, $replace,  json_encode($subject)));



}

?>



This method is almost 3x faster (in 10000 runs.) than using recursive calling and looping method, and 10x simpler in coding.



Compared to:



<?php

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

{

    if (is_array($subject))

    {

        foreach($subject as &$oneSubject)

            $oneSubject = str_replace_deep($search, $replace, $oneSubject);

        unset($oneSubject);

        return $subject;

    } else {

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

    }

}

?>

Wes Foster

6 years ago


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]

moostende at gmail dot com

4 years ago


Note that this does not replace strings that become part of replacement strings. This may be a problem when you want to remove multiple instances of the same repetative pattern, several times in a row.



If you want to remove all dashes but one from the string '-aaa----b-c-----d--e---f' resulting in '-aaa-b-c-d-e-f', you cannot use str_replace. Instead, use preg_replace:



<?php

$challenge = '-aaa----b-c-----d--e---f';

echo str_replace('--', '-', $challenge).'<br>';

echo preg_replace('/--+/', '-', $challenge).'<br>';

?>



This outputs the following:

-aaa--b-c---d-e--f

-aaa-b-c-d-e-f

Alberto Lepe

6 years ago


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"

jay_knows_(all)uk at hotmail dot com

5 years ago


This strips out horrible MS word characters. 

Just keep fine tuning it until you get what you need, you'll see ive commented some out which caused problems for me.

There could be some that need adding in, but its a start to anyone who wishes to make their own custom function.

<?php

function msword_conversion($str) 
{ 
$str = str_replace(chr(130), ',', $str);    // baseline single quote
$str = str_replace(chr(131), 'NLG', $str);  // florin
$str = str_replace(chr(132), '"', $str);    // baseline double quote
$str = str_replace(chr(133), '...', $str);  // ellipsis
$str = str_replace(chr(134), '**', $str);   // dagger (a second footnote)
$str = str_replace(chr(135), '***', $str);  // double dagger (a third footnote)
$str = str_replace(chr(136), '^', $str);    // circumflex accent
$str = str_replace(chr(137), 'o/oo', $str); // permile
$str = str_replace(chr(138), 'Sh', $str);   // S Hacek
$str = str_replace(chr(139), '<', $str);    // left single guillemet
// $str = str_replace(chr(140), 'OE', $str);   // OE ligature
$str = str_replace(chr(145), "'", $str);    // left single quote
$str = str_replace(chr(146), "'", $str);    // right single quote
// $str = str_replace(chr(147), '"', $str);    // left double quote
// $str = str_replace(chr(148), '"', $str);    // right double quote
$str = str_replace(chr(149), '-', $str);    // bullet
$str = str_replace(chr(150), '-–', $str);    // endash
$str = str_replace(chr(151), '--', $str);   // emdash
// $str = str_replace(chr(152), '~', $str);    // tilde accent
// $str = str_replace(chr(153), '(TM)', $str); // trademark ligature
$str = str_replace(chr(154), 'sh', $str);   // s Hacek
$str = str_replace(chr(155), '>', $str);    // right single guillemet
// $str = str_replace(chr(156), 'oe', $str);   // oe ligature
$str = str_replace(chr(159), 'Y', $str);    // Y Dieresis
$str = str_replace('°C', '&deg;C', $str);    // Celcius is used quite a lot so it makes sense to add this in
$str = str_replace('£', '&pound;', $str); 
$str = str_replace("'", "'", $str);
$str = str_replace('"', '"', $str);
$str = str_replace('–', '&ndash;', $str);

return $str;
}

?>

jbarnett at jmbelite dot com

6 years ago


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

6 years ago


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;
}
?>

markem at sim1 dot us

1 year ago


I was working with MySQL and displaying the title to things on the web page.  I'd written a script to ensure single and double quotes were removed from the title.  I used

    $title = str_replace( "'", "", $title );

and

     $title = str_replace( '"', "", $title );

But still the single and double quotes continued.  So I wrote a bit of code to print out each character separated by a dash.  Like so:

     for( $i=0; $i<strlen($title); $i++ ){
         echo "$i-";
         }

     echo "<br>\n";

This displayed:

     m-y-c-o-m-p-a-n-y- b-b-&-#-3-9-;-s

Which made me go "Oh!  I get it."

The MySQL function real_escape_string modifies the single quotes to be &#39; and double quotes as &#34;  These still show up as single and double quotes under HTML and most importantly - 

     JAVASCRIPT sees the &#34; and &#39; as actual single or double
     quotes.  So if you are passing arguments to a function you have
     to get rid of them or else you will get an error on trying to call
     a given function.  Example:

     <a href="javascript:func1('mycompany bbs&#39;s")'">

     becomes

     <a href="javascript:func1('mycompany bbs's');">

Which then will give you an error because there is a single quote inside of the single quoted string.  HOWEVER, the

     $title = str_replace( "'", "", $title );

WILL NOT FIND a single quote.  Instead, you have to do this:

     $title = str_replace( "&#39;", "'", $title );
and
     $title = str_relace( "&#34;", '"', $title );

(Or you could just get rid of them.)

So remember!  If you are trying to remove single and double quotes and are using MySQL and MySQL's real_escape_string() function that you might be having single and double quotes hanging around which are defined as &#39; and &#34; but which show up as single and double quotes as well as causing problems in your Javascripts.

kriscraig at php dot net

3 years ago


<?php



/**

 * Convert foreign 8859-1 characters into HTML entities.

 * 

 * @param string $str

 *   The string being parsed.

 * 

 * @return string

 *   The converted string.

 */

public static function convert_chars_to_entities( $str )

{

    $str = str_replace( 'À', '&#192;', $str );

    $str = str_replace( 'Á', '&#193;', $str );

    $str = str_replace( 'Â', '&#194;', $str );

    $str = str_replace( 'Ã', '&#195;', $str );

    $str = str_replace( 'Ä', '&#196;', $str );

    $str = str_replace( 'Å', '&#197;', $str );

    $str = str_replace( 'Æ', '&#198;', $str );

    $str = str_replace( 'Ç', '&#199;', $str );

    $str = str_replace( 'È', '&#200;', $str );

    $str = str_replace( 'É', '&#201;', $str );

    $str = str_replace( 'Ê', '&#202;', $str );

    $str = str_replace( 'Ë', '&#203;', $str );

    $str = str_replace( 'Ì', '&#204;', $str );

    $str = str_replace( 'Í', '&#205;', $str );

    $str = str_replace( 'Î', '&#206;', $str );

    $str = str_replace( 'Ï', '&#207;', $str );

    $str = str_replace( 'Ð', '&#208;', $str );

    $str = str_replace( 'Ñ', '&#209;', $str );

    $str = str_replace( 'Ò', '&#210;', $str );

    $str = str_replace( 'Ó', '&#211;', $str );

    $str = str_replace( 'Ô', '&#212;', $str );

    $str = str_replace( 'Õ', '&#213;', $str );

    $str = str_replace( 'Ö', '&#214;', $str );

    $str = str_replace( '×', '&#215;', $str );  // Yeah, I know.  But otherwise the gap is confusing.  --Kris

    $str = str_replace( 'Ø', '&#216;', $str );

    $str = str_replace( 'Ù', '&#217;', $str );

    $str = str_replace( 'Ú', '&#218;', $str );

    $str = str_replace( 'Û', '&#219;', $str );

    $str = str_replace( 'Ü', '&#220;', $str );

    $str = str_replace( 'Ý', '&#221;', $str );

    $str = str_replace( 'Þ', '&#222;', $str );

    $str = str_replace( 'ß', '&#223;', $str );

    $str = str_replace( 'à', '&#224;', $str );

    $str = str_replace( 'á', '&#225;', $str );

    $str = str_replace( 'â', '&#226;', $str );

    $str = str_replace( 'ã', '&#227;', $str );

    $str = str_replace( 'ä', '&#228;', $str );

    $str = str_replace( 'å', '&#229;', $str );

    $str = str_replace( 'æ', '&#230;', $str );

    $str = str_replace( 'ç', '&#231;', $str );

    $str = str_replace( 'è', '&#232;', $str );

    $str = str_replace( 'é', '&#233;', $str );

    $str = str_replace( 'ê', '&#234;', $str );

    $str = str_replace( 'ë', '&#235;', $str );

    $str = str_replace( 'ì', '&#236;', $str );

    $str = str_replace( 'í', '&#237;', $str );

    $str = str_replace( 'î', '&#238;', $str );

    $str = str_replace( 'ï', '&#239;', $str );

    $str = str_replace( 'ð', '&#240;', $str );

    $str = str_replace( 'ñ', '&#241;', $str );

    $str = str_replace( 'ò', '&#242;', $str );

    $str = str_replace( 'ó', '&#243;', $str );

    $str = str_replace( 'ô', '&#244;', $str );

    $str = str_replace( 'õ', '&#245;', $str );

    $str = str_replace( 'ö', '&#246;', $str );

    $str = str_replace( '÷', '&#247;', $str );  // Yeah, I know.  But otherwise the gap is confusing.  --Kris

    $str = str_replace( 'ø', '&#248;', $str );

    $str = str_replace( 'ù', '&#249;', $str );

    $str = str_replace( 'ú', '&#250;', $str );

    $str = str_replace( 'û', '&#251;', $str );

    $str = str_replace( 'ü', '&#252;', $str );

    $str = str_replace( 'ý', '&#253;', $str );

    $str = str_replace( 'þ', '&#254;', $str );

    $str = str_replace( 'ÿ', '&#255;', $str );

    

    return $str;

}

?>

matt wheaton

10 years ago


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);
?>

christof dot rieger at r-tron dot de

4 years ago


In many countries the numeric format is 1.000,33 in english it is 1,000.33

This function converts numeric arguments always into the PHP confirm numeric format. If only one seperator is into the numericstring so it is interpreted as the decimalpoint.

 function dp($zahl)
{
  if ((strpos($zahl,".") > "-1") | (strpos($zahl,",") > "-1")) {
    if ((strpos($zahl,".") > "-1") & (strpos($zahl,",") > "-1")) {
      if (strpos($zahl,".") > strpos($zahl,",")){
          return str_replace(",","",$zahl);
    } else {
          return str_replace(",",".",str_replace(".","",$zahl));
      }
  } else {
      if (strpos($zahl,".") > "-1") {
        if (strpos($zahl,".") == strrpos($zahl,".")) {
            return $zahl;
      } else {
          return str_replace(".","",$zahl);          
        } 
    } else {
        if (strpos($zahl,",") == strrpos($zahl,",")) {
          return str_replace(",",".",$zahl);
      } else {
          return str_replace(",","",$zahl);          
        } 
    } }
} else {
    return $zahl;
} }

Denzel Morris

4 years ago


Maybe obvious to veteran PHP programmers but less so to novice PHP programmers is the fact that this is invalid:
<?php
str_replace($search, $replace, $subject, 1);
?>
At a glance it appears to be a reasonable request, until you realize that the fourth parameter must be a variable in order to be passed as a reference. A replacement:
<?php
str_replace($search, $replace, $subject, $temp = 1);
// or
$temp = 1;
str_replace($search, $replace, $subject, $temp);
?>

mbullard at accuvista dot co dot uk

4 years ago


Insert space after comma.

If you have a form that stores results in a database field as comma separated values, when you display this data you can use the following to insert a space after each comma:

<?php
$find[] = ',';
$replace[] = '&#44;&nbsp;';
$text = str_replace($find, $replace, $row_rsRecordset['Field']);
print_r($text);
?>

Notes:
1) To get round the Replacement Order Gotcha, the comma is also replaced with its code equivalent: &#44;
2) You can adapt the $replace section to suit your needs: swap out the &nbsp; code with <br/> or replace comma and space with &nbsp;&middot;&nbsp; etc.

borasahin at gmail dot com

1 year ago


jSON Turkish Characters Problem - (PHP < 5.4 for example)

<?php
function json_decode_tr($json){
       $json_char = array("u00e7","u0131","u00fc","u011f","u00f6","u015f","u0130","u011e","u00dc","u00d6","u015e","u00c7");
       $turkish = array("ç","ı","ü","ğ","ö","ş","İ","Ğ","Ü","Ö","Ş","Ç");
       $result = str_replace($json_char, $turkish, $json);
       return json_decode($json);
    }
?>

David Holt

2 months ago


Be aware that if you use this for filtering & sanitizing some form of user input, or remove ALL instances of a string, there's another gotcha to watch out for:

// Remove all double characters
$string="1001011010";
$string=str_replace(array("11","00"),"",$string);
// Output: "110010"

$string="<ht<html>ml> Malicious code </<html>html> etc";
$string=str_replace(array("<html>","</html>"),"",$string);
// Output: "<html> Malicious code </html> etc"

mrrehbein at gmail dot com

1 year ago


nikolaz dot tang at hotmail dot com's solution of using json_encode/decode is interesting, but a couple of issues to be aware of with it.

<?php
// From: nikolaz dot tang at hotmail dot com's post
function str_replace_json($search, $replace, $subject){
     return json_decode(str_replace($search, $replace,  json_encode($subject)));
}
?> 

json_decode will return objects, where arrays are probably expected.  This is easily remedied by adding 2nd parameter 'true' to json_decode.

$search and $replace could contain strings that match json encoding, which will either change the structure returned by this method, or break the json.

ie:
<?php
var_dump(str_replace_json('":"', '","', ['this' => 'stuff']));
var_dump(str_replace_json('this":"', 'this" : "thing", "with":"', ['this' => 'stuff']));
?>

kkumar dot sandeep89 at gmail dot com

4 months ago


I came across requirement to replace some occurrences of a letter with other letter in a word:

<?php

$a =    'ctl00_ContentPlaceHolder1_Rpt_data_ctl01_lnk_name';
$b =    'ctl00$ContentPlaceHolder1$Rpt_data$ctl01$lnk_name';

echo "db has $a\n";
echo "we want $b\n";

//Make replacement array
$replacement = array(
    array('_','$'),
    array('_','$'),
    array('_','_'),
    array('_','$'),
    array('_','$'),
    array('_','$'),
);

//call function
echo replaceByArray($a,$replacement);

function replaceByArray($a, $replacement){
    $j=0;
    for($i=0; $i<strlen($a); $i++){
        if($a[$i]==$replacement[$j][0]){
            $a[$i] = $replacement[$j][1];    //make replacement
            $j++;        //increment index of replacement array
            if($j == (count($replacement)-1)) break;    //break out of loop if replacement array processed
        }
    }

    return $a;
}
?>

michael dot moussa at gmail dot com

7 years ago


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
?>

nick at NOSPAM dot pitchinteractive dot com

7 years ago


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;
    }
}
?>

Anonymous

9 years ago


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.

kole

9 years ago


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.

cc at cc dot com

4 years ago


I found a pretty low tech solution to avoid the "gotcha" without worrying about the array order of how things are replaced. I could not "order" the replacement array easily because it was being read from a database table.

Anyway if you add an identifiable token to each replaced word, then just filter this out at the very end, no nested search terms are found. I just dynamically add the %% after the first char of each word before pumping it into the str_ireplace function.

$find = array("as1", "as2", "as3", "flex");
$replace = array("<a href = \"#as1\">A%%uto S%%entry R%%ev. A%%</a>", "<a href = \"#as2\">A%%uto S%%entry E%%xp</a>", "<a href = \"#as3\">A%%uto S%%entry f%%lex</a>", "<a style = \"color: red;\" href = \"#flex\">f%%lex</a>");
$text = str_ireplace($find, $replace, $text);
echo str_ireplace("%%", "", $text);

In this case I am using %% as my token as this is an unlikely char combo for me.

apmuthu at usa dot net

5 years ago


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;
}

?>

cmbecker69 at gmx dot de

2 years ago


To collapse multiple consecutive space characters to a single one, don't use str_replace() inside a loop--use preg_replace() instead for clarity and better performance:

<?php

$str = ' This is    a    test   ';
$str = preg_replace('/ +/', ' ', $str);

?>

christian dot reinecke at web dot de

5 years ago


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.

Anonymous

2 years ago


@moostende at gmail dot com
If you want to remove all dashes but one from the string '-aaa----b-c-----d--e---f' resulting in '-aaa-b-c-d-e-f', you CAN use str_replace !

<?php
function foo($str)
{
    do {
        $str = str_replace("--", "-", $str, $count);
    } while ($count > 0);
    return $str;
}
echo foo("-aaa----b-c-----d--e---f");
?>

This outputs the following: 
-aaa-b-c-d-e-f

mevdschee

5 years ago


say you want every "a" replaced by "abba" and every "b" replaced by "baab" in the string "ab" you do:



<?php

$search = array("a","b");

$replace = array("abba","baab");

echo str_replace($search,$replace,"ab");

?>



that results in "abaabbaababaab" and not the expected "abbabaab"



I wrote this little snippet to solve the replacements-in-replacement problem:



<?php

function search_replace($s,$r,$sql)

{ $e = '/('.implode('|',array_map('preg_quote', $s)).')/';

  $r = array_combine($s,$r);

  return preg_replace_callback($e, function($v) use ($s,$r) { return $r[$v[1]]; },$sql);

}



echo search_replace($search,$replace,"ab");

?>



that results in the expected "abbabaab"

troy at troyonline dot com

7 years ago


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;
    }
?>

moz667 at gmail dot com

6 years ago


<?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);

?>

David Gimeno i Ayuso (info at sima dot cat)

8 years ago


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 )

?>

hakre

4 years ago


I was looking for a str_replace function supporting callbacks. As I didn't found one I wrote one my own. Works exactly like str_replace, but the replace parameter is a callback or an array of callbacks (instead of string/strings in str_replace). The callback function accepts two arguments, the string that is being replaced and the count of the replacement being done.

<?php
/**
 * str_ureplace
 * 
 * str_replace like function with callback
 * 
 * @param string|array search
 * @param callback|array $replace
 * @param string|array $subject
 * @param int $replace_count
 * @return string|array subject with replaces, FALSE on error.
 */
function str_ureplace($search, $replace, $subject, &$replace_count = null) {
    $replace_count = 0;
    
    // validate input
    $search = array_values((array) $search);
    $searchCount = count($search);
    if (!$searchCount) {
        return $subject;
    }
    foreach($search as &$v) {
        $v = (string) $v;
    }
    unset($v);
    $replaceSingle = is_callable($replace);    
    $replace = $replaceSingle ? array($replace) : array_values((array) $replace);
    foreach($replace as $index=>$callback) {
        if (!is_callable($callback)) {
            throw new Exception(sprintf('Unable to use %s (#%d) as a callback', gettype($callback), $index));
        }
    }
    
    // search and replace
    $subjectIsString = is_string($subject);
    $subject = (array) $subject;
    foreach($subject as &$haystack) {
        if (!is_string($haystack)) continue;
        foreach($search as $key => $needle) {
            if (!$len = strlen($needle))
                continue;            
            $replaceSingle && $key = 0;            
            $pos = 0;
            while(false !== $pos = strpos($haystack, $needle, $pos)) {
                $replaceWith = isset($replace[$key]) ? call_user_func($replace[$key], $needle, ++$replace_count) : '';
                $haystack = substr_replace($haystack, $replaceWith, $pos, $len);
            }
        }
    }
    unset($haystack);
    
    return $subjectIsString ? reset($subject) : $subject;
}
?>

Ing. Mirko Plazotta

1 year ago


<?php
// a very beatiful way to do multiple replacements is this one, using just one array
$replaceThis = Array(
'old word' => 'new word',
'was' => 'it',
'past' => 'future',
);

$originalText = "every old word was a thing of the past...";
$replacedText = str_replace(array_keys($replaceThis), $replaceThis, $originalText);
echo $replacedText;
?>

karst at onlinq dot nl

1 year ago


"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. "

I think one important (and not at all vaguely theoretical) use-case is completely ignored here. Take, for example, the way the PDO handles parameter replacement.

If we have the following query:
"SELECT * FROM my_table WHERE (id = ? AND my_column = ? AND other_column = ?);"
The "?"s should be replaced by each successive variable in a $parameters array. That is EXACTLY the use case for "search" being a value and "replace" being an array. 

Considering that this is not only a real-world example but also part of a core PHP functionality I find it very strange that it's dismissed so easily here.

Decko

6 years ago


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 == '/'
?>

abc dot abc1 at vp dot pl

2 years ago


I have:

<?php
function lacz_bd()
{  
  $db = new mysqli('localhost', '_admin', 'pass', 'db'); 
  
  if (! $db)
      return false;
   $db->autocommit(TRUE);
   return $db;
}
// dane do ramy pliku .xml
$kanalRSS = '<?xml version="1.0" encoding="ISO-8859-2"?>';
$kanalRSS .= '<trovit>';
$kanalRSS .= '<ad>';

// połaczenie z bazą danych
$db = lacz_bd();
//zapytanie określające dane ktore powinny byc pobrane z tabeli
// teraz pobierzmy wszystkie dane spelniajace warunek category_id=140
$zapytanie = "SELECT * FROM announcements WHERE category_id in (140,141,142,143,144)";
$wynik = $db->query($zapytanie);
$ile_znalezionych = $wynik->num_rows;

for ($i=0; $i <$ile_znalezionych; $i++)
        {
        $wiersz = $wynik->fetch_assoc();
        
        //usuwamy znaczniki html ze wszystkich danych z tabeli, polskie znaki, duze litery
        $string_title = $wiersz['annoucement_title'];
        $string_url = $wiersz['annoucement_title'];
        $pattern = array(' ', ',', '.', '/ą/', '/Ą/', '/ć/', '/Ć/', '/ę/', '/Ę/', '/ł/', '/Ł/' ,'/ń/', '/Ń/', '/ó/', '/Ó/', '/ś/', '/Ś/', '/ź/', '/Ź/', '/ż/', '/Ż/',);
        $replacement = array('-', '', '',     'a', 'A', 'c', 'C', 'e', 'E', 'l', 'L', 'n', 'N', 'o', 'O', 's', 'S', 'z', 'Z', 'z', 'Z',);
        $string_url = strtolower(str_replace($pattern, $replacement, $string_url));
            
        $wiersz['annoucement_content'] = strip_tags($wiersz['annoucement_content']);
        //dodajemy nazwy rodzajow ogloszenia
        $string_type = $wiersz['annoucement_type'];
        $_type = array('1', '2', '3', '4');
        $_new_type = array('Buy', 'Replace', 'For Rent', 'For Sale');
        $wiersz['annoucement_type'] = str_replace($_type, $_new_type, $string_type);
                
//tutaj generujemy zawartosc pliku .xml, ktora pobierana jest z tabeli announcements
        $kanalRSS .= '<item>';
    $kanalRSS .= '<id><![CDATA['.$wiersz['annoucement_id'].']]></id>';
    $kanalRSS .= '<url><![CDATA[http://oglaszajtu.pl/ogloszenia/'.$wiersz['annoucement_id'].'/'.$string_url.']]></url>';
    $kanalRSS .= '<title><![CDATA['.$string_title.']]></title>';
    $kanalRSS .= '<type><![CDATA['.$wiersz['annoucement_type'].']]></type>';
    $kanalRSS .= '<content><![CDATA['.$wiersz['annoucement_content'].']]></content>';
    $kanalRSS .= '<date><![CDATA['.$wiersz['annoucement_date_added'].']]></date>';
        $kanalRSS .= '</item>';
                }
    $kanalRSS .= ' </ad>';
$kanalRSS .= '</trovit>';

//Zapisujemy wygenerowany kod XML do pliku moj_rss.xml
$fp = fopen('trovit_oglaszajtu.xml','w');
fwrite($fp,$kanalRSS);
fclose($fp);
?>

And one problem - ą,ó,ś, etc - don't delete

oglaszajtu.pl/moj_rss.php
oglaszajtu.pl/trovit_oglaszajtu.xml

:-(
Can anyone help me?
Thx
rel

bfrohs at gmail dot com

3 years ago


This function implements $limit for str_replace(); is 100% backward compatible with str_replace(); uses str_replace() whenever possible (for performance reasons); supports arrays for $search, $replace, and $subject; and is fully commented.

<?php
/**
 * Replace $limit occurences of the search string with the replacement
 * @param mixed $search The value being searched for. An array may be used to
 * designate multiple needles.
 * @param mixed $replace The replacement value that replaces found search
 * values. An array may be used to designate multiple replacements.
 * @param mixed $subject The string or array being searched and replaced on. 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. 
 * @param string $count If passed, this will be set to the number of
 * replacements performed.
 * @param int $limit The maximum possible replacements for each pattern in each
 * subject string. Defaults to -1 (no limit).
 * @return string This function returns a string with the replaced values.
 */
function str_replace_limit($search, $replace, $subject, &$count, $limit = -1){
 $count = 0;
 // Invalid $limit provided
 if(!($limit===strval(intval(strval($limit))))){
  trigger_error('Invalid $limit `'.$limit.'` provided. Expecting an '.
    'integer', E_USER_WARNING);
  return $subject;
 }
 // Invalid $limit provided
 if($limit<-1){
  trigger_error('Invalid $limit `'.$limit.'` provided. Expecting -1 or '.
    'a positive integer', E_USER_WARNING);
  return $subject;
 }
 // No replacements necessary
 if($limit===0){
  trigger_error('Invalid $limit `'.$limit.'` provided. Expecting -1 or '.
    'a positive integer', E_USER_NOTICE);
  return $subject;
 }
 // Use str_replace() when possible
 if($limit===-1){
  return str_replace($search, $replace, $subject, $count);
 }
 if(is_array($subject)){
  // Loop through $subject values
  foreach($subject as $key => $this_subject){
   // Skip values that are arrays
   if(!is_array($this_subject)){
    // Call this function again
    $this_function = __FUNCTION__;
    $subject[$key] = $this_function($search, $replace, $this_subject, $this_count, $limit);
    // Adjust $count
    $count += $this_count;
    // Adjust $limit
    if($limit!=-1){
     $limit -= $this_count;
    }
    // Reached $limit
    if($limit===0){
     return $subject;
    }
   }
  }
  return $subject;
 } elseif(is_array($search)){
  // Clear keys of $search
  $search = array_values($search);
  // Clear keys of $replace
  if(is_array($replace)){
   $replace = array_values($replace);
  }
  // Loop through $search
  foreach($search as $key => $this_search){
   // Don't support multi-dimensional arrays
   $this_search = strval($this_search);
   // If $replace is an array, use $replace[$key] if exists, else ''
   if(is_array($replace)){
    if(array_key_exists($key, $replace)){
     $this_replace = strval($replace[$key]);
    } else {
     $this_replace = '';
    }
   } else {
    $this_replace = strval($replace);
   }
   // Call this function again for
   $this_function = __FUNCTION__;
   $subject = $this_function($this_search, $this_replace, $subject, $this_count, $limit);
   // Adjust $count
   $count += $this_count;
   // Adjust $limit
   if($limit!=-1){
    $limit -= $this_count;
   }
   // Reached $limit
   if($limit===0){
    return $subject;
   }
  }
  return $subject;
 } else {
  $search = strval($search);
  $replace = strval($replace);
  // Get position of first $search
  $pos = strpos($subject, $search);
  // Return $subject if $search cannot be found
  if($pos===false){
   return $subject;
  }
  // Get length of $search
  $search_len = strlen($search);
  // Loop until $search cannot be found or $limit is reached
  for($i=0;(($i<$limit)||($limit===-1));$i++){
   $subject = substr_replace($subject, $replace, $pos, $search_len);
   // Increase $count
   $count++;
   // Get location of next $search
   $pos = strpos($subject, $search);
   // Break out of loop
   if($pos===false){
    break;
   }
  }
  return $subject;
 }
}
?>

fleshgrinder at gmx dot at

6 years ago


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);
}

?>

paolo A T doppioclick D O T com

7 years ago


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

cableray

5 years ago


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.

nospam at nospam dot com

7 years ago


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

str_replace

Description

Parameters

Return Values

Examples

Notes

Replacement order gotcha

See Also

User Contributed Notes