String Functions
PHP Manual


(PHP 4, PHP 5, PHP 7)

str_replaceReplace all occurrences of the search string with the replacement string


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().


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.


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


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


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.


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.


Example #1 Basic str_replace() examples

// 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);

Example #2 Examples of potential str_replace() gotchas

// 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';

// 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);


Note: This function is binary-safe.


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.


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

See Also

String Functions
PHP Manual