str_repeat
I'm sorry. I can't believe it: I messed up again. Something that I forgot is that the php empty() function considers the number zero (0) as an empty value. Therefore, we need to change our if statement to the following:
<?php
if ($i[0] !== null) $subject .= $replace[$i[0]];
?>
If we left it how it was, the replace ignores the first element of the arrays. ($array[0])
The reason that I used !empty() before, is that I wasn't sure what array_keys() returns if the element is not found (null? and empty string?), since both null and the empty string print out the same and I couldn't find what it returned in this case, in the manual.
The final, working function would look like:
<?php
function str_replace_once($search, $replace, $subject) {
$newArr = str_split($subject);
$subject = '';
foreach ($newArr as $nchar)
{
$i = array_keys($search, $nchar);
if ($i[0] !== null) $subject .= $replace[$i[0]];
else $subject .= $nchar;
}
return $subject;
}
?>
str_replace
(PHP 4, PHP 5)
str_replace — Sustitiye todas las apariciones de una cadena en otra
Descripción
mixed str_replace
( mixed $cadena_buscada
, mixed $cadena_sustituta
, mixed $cadena_original
[, int &$veces
] )
Esta función sustituye todas las apariciones de la cadena_buscada en la cadena cadena_original por la cadena_sustituta dada. Si no precisa reglas especiales de sustitución (como por ejemplo expresiones regulares), deberá usar siempre esta función en lugar de ereg_replace() o preg_replace().
Desde la versión de PHP 4.0.5, todos los parámetros de la función pueden ser de tipo array.
Warning
En las versiones de PHP anteriores a la 4.3.3, existí un error cuando se empleaban matrices como parámetros cadena_buscada y cadena_sustituta que hacía que no se tuvieran en cuenta los índices vacíos de cadena_buscada y por tanto no se avanzara en la matriz de forma sincronizada con la otra matriz cadena_sustituta . Los scripts que estaban preparados para tratar este error, deben eliminar los valores vacíos de cadena_buscada antes de llamar a esta función para mantener el comportamiento original de la función.
Si cadena_original es una matriz, la búsqueda y sustitución se realiza en cada una de las entradas de cadena_original y por tanto, el valor devuelto también es una matriz.
Si cadena_buscada y cadena_sustituta son matrices, la función str_replace() selecciona cada vez un valor de ambas matrices y realiza la búsqueda/sustitución. Si cadena_buscada tiene menos elementos que cadena_sustituta , se emplea una cadena vacía para realizar el resto de sustituciones. Si cadena_buscada es una matriz y cadena_sustituta es una cadena, se emplea esta cadena para realizar la sustición de todos los valores de cadena_buscada .
Example #1 Ejemplo de str_replace()
<?php
// Obtiene: <body text='black'>
$etiqueta_body = str_replace("%body%", "black", "<body text='%body%'>");
// Obtiene: Hl Mnd d PHP
$vocales = array("a", "e", "i", "o", "u", "A", "E", "I", "O", "U");
$solo_consonantes = str_replace($vocales, "", "Hola Mundo de PHP");
// Obtiene: Debes comer pizza, cerveza y helados todos los dias
$frase_original = "Debes comer frutas, verduras y fibra todos los dias";
$sano = array("frutas", "verduras", "fibra");
$sabroso = array("pizza", "cerveza", "helados");
$nueva_frase = str_replace($sano, $sabroso, $frase_original);
// El parametro "veces" esta disponible desde la version de PHP 5.0.0
$cadena = str_replace("ll", "", "yo llevaba la llave", $numero_veces);
echo $numero_veces; // El valor de $numero_veces es: 2
?>
Note: Esta función es segura binariamente.
Note: Desde la versión de PHP 5.0.0 el número de cadenas encontradas y sustituidas se devuelve en el parámetro veces , que se pasa por referencia. En las versiones anteriores a PHP 5.0.0, este parámetro no está disponible.
Vea también str_ireplace(), substr_replace(), ereg_replace(), preg_replace() y strtr().
add a note
User Contributed Notesstr_replace
max at efoxdesigns dot com
07-Aug-2008 06:13
07-Aug-2008 06:13
max at efoxdesigns dot com
07-Aug-2008 05:28
07-Aug-2008 05:28
Sorry, folks. That last note I put up won't work quite correctly. Unlike str_replace(), that snippet I showed you will replace any characters that aren't in your $search array with an empty string.
To correct this behavior, add this check to the foreach loop:
<?php
//...
if (!empty($i[0])) $subject .= $replace[$i[0]];
else $subject .= $nchar; //now, if the search character isn't found (ie, we don't care about it), it will stay the same, instead of getting replaced by an empty string.
?>
The whole thing would look like the following, if you were to put it into a function:
<?php
function char_replace_once($search, $replace, $subject) {
$newArr = str_split($subject);
$subject = '';
foreach ($newArr as $nchar)
{
$i = array_keys($search, $nchar);
if (!empty($i[0])) $subject .= $replace[$i[0]];
else $subject .= $nchar;
}
return $subject;
}
?>
I'm sure it may not be as efficient as str_replace(), but it successfully replaces characters, correctly.
ONE OTHER IMPORTANT THING TO NOTE: Unlike I said before, this will only work for character replacement - not string replacement. The reason, of course, is that the original string gets split into an array, who's members are only one character. Sorry about that.
That drawback aside, though, this is still a useful function for doing complete, accurate character replacement.
max at efoxdesigns dot com
07-Aug-2008 04:29
07-Aug-2008 04:29
Note that the str_replace() function is recursive. This is not usually a problem, unless you are trying to do a replace in which a character or string occurs in the $search array, after the same character or string occurs in the $replace array. (For instance, imagine doing a global character replace.)
To demonstrate, take a look at the folowing:
<?php
$search = array('q','w','e','r','t','y','u');
$replace = array('z','s','d','e','y','f','g');
$mystring = 'qwertyu';
//Outputs: zsdeffg
echo str_replace($search, $replace, $mystring);
?>
As you would expect, the q gets replaced by a z, the w by an s, and so on. Everything is correct, except that the t doesn't seem to have been replaced by a y. This is not entirely true, however. What happened is that it did, indeed get replaced by a y, but then on the next pass of the str_replace() function, str_replace() found a y and replaced it with an f.
To get this to work as we'd like (every letter in the $search array replaced by the cooresponding spot in the $replace array), we can do something like the following:
<?php
$search = array('q','w','e','r','t','y','u');
$replace = array('z','s','d','e','y','f','g');
$mystring = 'qwertyu';
//Outputs: zsdeffg (Not what we wanted.)
echo str_replace($search, $replace, $mystring);
$newArr = str_split($mystring); //split $mystring into an array of characters. For php4, you'll have to create the str_split() function.
$newstring = '';
foreach ($newArr as $nchar)
{
$i = array_keys($replace, $nchar); //get the key(s) in the $search array for the character we're replacing. (we assume it occurs only once.) Returns an array of length, 1.
$newstring .= $replace[$i[0]]; //find the character in the $replace array that matches the position of the one we're replacing, and add it to $newstring.
}
//Outputs: zsdeyfg
echo $newstring;
?>
This time, as you can see, there is a y in place of the t, which was what we wanted. :)
Hope that clears up any confusion for anyone wondering why their strings aren't getting replaced as they'd expect.
troy at troyonline dot com
23-Jun-2008 03:18
23-Jun-2008 03:18
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 $subject;
}
?>
jaimthorn at yahoo dot com
20-Jun-2008 09:52
20-Jun-2008 09:52
On the 19th of June, 2008, max at bitsonnet dot com posted a function interpolate that used create_function. I'd never seen create_function before and I thought it was very educational. Thanks, Maxim!
However, the interpolate function can be improved, speed-wise:
<?php
function interpolate2($template, $hash, $prefix = '#{', $postfix = '}')
{
$tmp = array();
foreach($hash as $k => $v)
{
$tmp[$prefix . $k . $postfix] = $v;
}
return str_replace(array_keys($tmp), array_values($tmp), $template);
}
echo interpolate2('Hello, #{username}. Welcome to #{site}.', array('username' => 'World', 'site' => 'php.net'));
?>
According to my own tests, this version is somewhere between 4 and 5 times faster.
Note, btw, that I used a very similar function on the sprintf page.
max at bitsonnet dot com
20-Jun-2008 07:00
20-Jun-2008 07:00
I always miss interpolate functionality in PHP, so I wrote this little helper method. It allows you to specify your own markup using $prefix and $postfix.
<?php
# Interpolate a string using hash.
# by Maxim Chernyak ( http://mediumexposure.com )
function interpolate($template, $hash, $prefix = '#{', $postfix = '}' ) {
$tokenize = create_function('$token', 'return "'. $prefix .'".$token."'.$postfix.'";');
$keys = array_keys($hash);
$values = array_values($hash);
$keys = array_map($tokenize, $keys);
return str_replace($keys, $values, $template);
}
?>
For example:
<?php
$result = interpolate('Hello, #{username}. Welcome to #{site}.', array('username' => 'Hakunin', 'site' => 'php.net'));
?>
cclarkson at htcomp dot net
28-Apr-2008 08:32
28-Apr-2008 08:32
The example presented by bladescope at googlemail dot com has a couple of syntax errors. This works:
<?php
$template = "The {color} {object} is in {location}";
$array = array(
'{object}' => 'Ball',
'{color}' => 'Red',
'{location}' => 'The Playground',
);
foreach ($array as $search => $replace) {
$template = str_replace($search, $replace, $template);
}
print $template;
?>
I did not check it for speed or thoroughly test it, but this function seems to do the same thing more succinctly.
<?php
function template($array, $template) {
return str_replace(
array_keys($array),
array_values($array),
$template
);
}
echo template(
array(
'{color}' => 'red',
'{object}' => 'ball',
'{location}' => 'the playground',
),
'The {color} {object} is in {location}.'
);
?>
David Gimeno i Ayuso (info at sima dot cat)
10-Aug-2007 05:50
10-Aug-2007 05:50
This is the functions I wrote for the problem reported above, str_replace in multi-dimensional arrays. It can work with preg_replace as well.
<?php
function array_replace($SEARCH,$REPLACE,$INPUT) {
if (is_array($INPUT) and count($INPUT)<>count($INPUT,1)):
foreach($INPUT as $FAN):
$OUTPUT[]=array_replace($SEARCH,$REPLACE,$FAN);
endforeach;
else:
$OUTPUT=str_replace($SEARCH,$REPLACE,$INPUT);
endif;
return $OUTPUT;
}
?>
David Gimeno i Ayuso (info at sima dot cat)
10-Aug-2007 05:22
10-Aug-2007 05:22
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 )
?>
mjaque at ilkebenson dot com
22-Jul-2007 06:28
22-Jul-2007 06:28
In order to replace carriage return characters from form inputs, if everything else fails, you can try:
<?php
$new_text = str_replace(chr(13).chr(10), '_', $original_text);
?>
And in order to show the line feeds in a javascript alert, you can do:
<?php
$new_text = str_replace(chr(13).chr(10), '\n', $original_text);
?>
cm at k-a-p dot com
13-Jun-2007 11:47
13-Jun-2007 11:47
Here is a version that allows for empty multidimensional arrays:
<?php
function str_replace_array ($search, $replace, $subject) {
if (is_array($subject)) {
foreach ($subject as $id=>$inner_subject) {
$subject[$id]=str_replace_array($search, $replace, $inner_subject);
}
} else {
$subject=str_replace($search, $replace, $subject);
}
return $subject;
}
?>
tim at hysniu dot com
06-Jun-2007 04:27
06-Jun-2007 04:27
I found that having UTF-8 strings in as argument didnt
work for me using heavyraptors function.
Adding UTF-8 as argument on htmlentities
fixed the problem.
cheers, tim at hysniu.com
<?php
function replace_accents($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
26-Feb-2007 12:48
26-Feb-2007 12:48
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, $strFromExcelFile);
Works for me.
rlee0001 at sbcglobal dot net
17-Feb-2007 07:30
17-Feb-2007 07:30
This is a more rigid alternative to spectrereturns at creaturestoke dot com's replace_different function:
<?php
function str_replace_many ($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, $search much be exactly one character (if a string is provided, only the first character in the string will be used). Examples:
<?php
echo str_replace_many('?',array('Jane','banana'),'? is eating a ?.');
?>
prints: "Jane is eating a banana."
15-Jan-2007 08:42
Before spending hours searching your application why it makes UTF-8 encoding into some malformed something with str_replace, make sure you save your PHP file in UTF-8 (NO BOM).
This was at least one of my problems.
Boris DOT Christ AT laposte DOT net
28-Nov-2006 08:32
28-Nov-2006 08:32
I create a little function to transform (to example) "User@example.net" in "user AT example DOT net" and conversely.
<?php
function code_mail($email) {
if(preg_match('`^.+@.+\..{1,5}$`', $email)) { //email format
$email = str_replace('.', ' DOT ', $email); //replace . by dot
$email = str_replace('@', ' AT ', $email); //replace @ by at
return $email;
}
else { //not email format
return false;
}
}
function decode_mail($email) { //on décode...
$email = str_replace(' DOT ', '.', $email); //replace dot by .
$email = str_replace(' AT ', '@', $email); //replace at by @
return $email;
}
?>
Ota L.
11-Nov-2006 10:14
11-Nov-2006 10:14
This simple function may be usefull to convert czech text from cp-1250 encoding to iso-8859-2 (convert S, T and Z with caron).
I use it because mbstring does not support windows-1250 (i.e. mb_convert_encoding(win2iso($text), "utf-8", "iso-8859-2");).
<?php
function win2iso($text)
{
$win = array ("\x9A", "\x9D", "\x9E", "\x8A", "\x8D", "\x8E");
$iso = array ("\xB9", "\xBB", "\xBE", "\xA9", "\xAB", "\xAE");
return str_replace($win, $iso, $text);
}
?>
webmaster at unitedscripters dot com
30-Jul-2006 11:50
30-Jul-2006 11:50
You may have decided to save in a non ANSI format a file so that a few fancy chars that you plan to replace can be viewed by your human eyes too (aren't all those empty rectangles a curse?).
Fine. All works just fine in the file, and all the replacements occur as intended.
You make a class out of those codes.
Then you put this non ANSI encoded file in your includes folder. Isn't it a nice class?
Well, don't call in such class as an include into another file, if the latter is ANSI : the char look up tables will NOT match, and the latter file (say the caller) will (I guess) feed ANSI codes to the included file (say the called) and you will spend a day wondering why the class methods work 100% well when you perform replacements directly from within the called, and yet the very same methods, even with the very same copied-and-pasted examples, fail miserably when performed from within the caller.
A very "stimulating" debugging!
I just came out from a night spent on this. I just forgot the included class file wasn't saved as an ANSI.
<?php
class regexp{
//blah blah...
var $toascii=array( 'Ã' => 'A');
//blah blah
function toascii_replace($input, $addSlashes=0){
return (!$addSlashes)? strtr($input, $this->toascii): addslashes( strtr($input, $this->toascii) );
}
}
$r=new regexp();
$input='Ã';
print $r->toascii_replace($input);//prints A
?>
Now save that class (remove the print statement too) in a format that isn't ANSI, say UTF-8.
Then do:
<?php
include_once('regexp.php');
$r=new regexp();
$input='Ã';
print $r->toascii_replace($input);//prints... Ã
?>
IDENTICAL codes, different results.
note: the class uses strtr but would happen with all replacing oriented functions, and I can pester all the documentations. Maybe I worked out the wrong reason, but the behaviour occurs.
matt wheaton
31-Mar-2006 02:40
31-Mar-2006 02:40
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 †for the right side double smart quote that doesn't seem to display here. It is chr(157).
<?php
$find[] = '“'; // left side double smart quote
$find[] = 'â€'; // right side double smart quote
$find[] = '‘'; // left side single smart quote
$find[] = '’'; // right side single smart quote
$find[] = '…'; // elipsis
$find[] = '—'; // em dash
$find[] = '–'; // en dash
$replace[] = '"';
$replace[] = '"';
$replace[] = "'";
$replace[] = "'";
$replace[] = "...";
$replace[] = "-";
$replace[] = "-";
$text = str_replace($find, $replace, $text);
?>
hermes at andycostell dot com
12-Dec-2004 06:57
12-Dec-2004 06:57
A simple function to take out the double line breaks "%0D%0A" from a string made from text being wrapped in a textarea and turn them into single line breaks.
<?php
function remove_extra_linebreaks($string) {
$new_string=urlencode ($string);
$new_string=ereg_replace("%0D", " ", $new_string);
$new_string=urldecode ($new_string);
return $new_string;
}
?>
I use it when taking text from a textarea with wrap="hard" that I'm emailing out on the next page, for instance. Otherwise there's an extra empty line between each line in the emailed text, which looks nasty!
David Gimeno i Ayuso (info at sima-pc dot com)
25-Aug-2003 11:12
25-Aug-2003 11:12
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".
imho at auspantheon dot com
27-Jun-2003 09:08
27-Jun-2003 09:08
An excellent way of making sure your pages don't contain "invalid entities", IE. Valid HTML is using the following function.
Most forum packages / extensions provide output containing the symbol &, we don't want this!
<?php
function include_safe ($file)
{
$array = file($file);
foreach ($array as $line) {
print str_replace('&', '&', $line);
}
}
?>
The same technique could also be used in conjuntion with htmlmspecialchars or htmlentities.
13-Jun-2003 08:59
Having a string for $search and an array for $replace won't work. This is mentioned on the preg_replace() page where it's described as not making sense, but not here.
But one could interpret such a situation and hence implement str_replace so that a signature of (string, array, string) or even (string, array, array) would "work". The result of
<?php
$search = '*';
$replace = range(1,20);
$subject = '{*}';
$result = str_replace($search, $replace, $subject);
?>
could be an array of elements "{1}", "{2}", "{3}" .... In other words it would have the same effect as
<?php
$search = '*';
$replace = range(1,20);
$subject = '{*}';
$result = array();
foreach($replace as $r) {
$result[] = str_replace($search, $r, $subject);
}
?>
I leave more elaborate applications to your imagination :)
The result of a str_replace(string,array,array) would therefore presumably be an array of arrays, with its dimensions indexed by the two arrays passed in. But then there's the question of which is the first dimension and which is the second.
rit at NOSPAMchatol dot com
07-Jan-2003 11:32
07-Jan-2003 11:32
I was trying to remove newlines from a textarea input (result of failed submission of parent form - JS verification not possible in this situation) to send back to the textarea via javascript (due to the fact that setting the value in the textarea tag does not work) and had a hard time figuring it out.
If anyone cares, try replacing: "%0D%0A" which is how I found it(changed my POST method to GET) and tracked it down in the address bar of my browser. Hope this helps, I sure wish someone else had posted it earlier!
art at zollerwagner dot com
10-Oct-2002 08:26
10-Oct-2002 08:26
To use one or two arrays in str_replace,
this appears to be the correct format:
<?php
str_replace(array('1st_current_needle_element', '2nd', '3rd'), array('1st_new_needle_element', '2nd', '3rd'), $haystack)
?>
Example of a single array, which simply removes the characters in the first array:
<?php
$text=str_replace(array('<', '>', '\\', '/', '='), "", $text);
?>
This will delete the chars: < > \ / =
It could also be done by first defining the array(s), like this:
<?php
$targetChars=array('<', '>', '\\', '/', '=');
$text=str_replace($targetChars, "", $text);
?>