function str_replace2($find, $replacement, $subject, $limit = 0){ if ($limit == 0) return str_replace($find, $replacement, $subject); $ptn = '/' . preg_quote($find,'/') . '/'; return preg_replace($ptn, $replacement, $subject, $limit); } 

Это позволит вам установить ограничение на количество замен. Строки должны быть экранированы с помощью preg_quote чтобы убедиться, что любые специальные символы не интерпретируются как символ шаблона.

Демо, BTW

Если вам интересно, вот версия, которая включает аргумент &$count :

 function str_replace2($find, $replacement, $subject, $limit = 0, &$count = 0){ if ($limit == 0) return str_replace($find, $replacement, $subject, $count); $ptn = '/' . preg_quote($find,'/') . '/'; return preg_replace($ptn, $replacement, $subject, $limit, $count); } 

Theres лучший способ сделать это

 <? $str = 'abcdef abcdef abcdef'; // pattern, replacement, string, limit echo preg_replace('/abc/', '123', $str, 1); // outputs '123def abcdef abcdef' ?> 

 $str = implode($replace, explode($search, $subject, $count + 1)); 

Быстрый PoC:

 $str = "To be, or not to be, that is the question: Whether 'tis Nobler in the mind to suffer The Slings and Arrows of outrageous Fortune, Or to take Arms against a Sea of troubles, And by opposing end them"; /* Replace the first 2 occurrences of 'to' with 'CAN IT' in $str. */ echo implode('CAN IT', explode('to', $str, 3)); 

Выход (выделено мной):

Быть или не МОЖЕТ быть, вот в чем вопрос:
Является ли это умником в уме
Стропы и стрелы возмутительной удачи,
Или взять Оружие против моря неприятностей,
И противопоставляя их конец

Обратите внимание, что этот метод чувствителен к регистру.

Первоначально вытащен из https://stackoverflow.com/a/11400172/526741

Я написал функцию, которая на 100% обратно совместима с str_replace() . То есть вы можете заменить все вхождения str_replace() на str_replace_limit() без каких-либо str_replace_limit() , даже с использованием массивов для $search , $replace и / или $subject .

Функция может быть полностью автономной, если вы хотите заменить вызов функции ($string===strval(intval(strval($string)))) , но я бы рекомендовал против него, поскольку valid_integer() является довольно полезная функция при работе с целыми числами, представленными в виде строк.

Примечание. Если возможно, str_replace_limit() будет использовать str_replace() вместо этого, поэтому все вызовы str_replace() могут быть заменены на str_replace_limit() не беспокоясь о достижении производительности.

Применение

 <?php $search = 'a'; $replace = 'b'; $subject = 'abcabc'; 

 $limit = -1; // No limit $new_string = str_replace_limit($search, $replace, $subject, $count, $limit); echo $count.' replacements -- '.$new_string; 

2 замены – bbcbbc

 $limit = 1; // Limit of 1 $new_string = str_replace_limit($search, $replace, $subject, $count, $limit); echo $count.' replacements -- '.$new_string; 

1 замена – bbcabc

 $limit = 10; // Limit of 10 $new_string = str_replace_limit($search, $replace, $subject, $count, $limit); echo $count.' replacements -- '.$new_string; 

2 замены – bbcbbc

функция

 <?php /** * Checks if $string is a valid integer. Integers provided as strings (eg '2' vs 2) * are also supported. * @param mixed $string * @return bool Returns boolean TRUE if string is a valid integer, or FALSE if it is not */ function valid_integer($string){ // 1. Cast as string (in case integer is provided) // 1. Convert the string to an integer and back to a string // 2. Check if identical (note: 'identical', NOT just 'equal') // Note: TRUE, FALSE, and NULL $string values all return FALSE $string = strval($string); return ($string===strval(intval($string))); } /** * Replace $limit occurences of the search string with the replacement string * @param mixed $search The value being searched for, otherwise known as the needle. 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, 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. * @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 ){ // Set some defaults $count = 0; // Invalid $limit provided. Throw a warning. if(!valid_integer($limit)){ $backtrace = debug_backtrace(); trigger_error('Invalid $limit `'.$limit.'` provided to '.__function__.'() in '. '`'.$backtrace[0]['file'].'` on line '.$backtrace[0]['line'].'. Expecting an '. 'integer', E_USER_WARNING); return $subject; } // Invalid $limit provided. Throw a warning. if($limit<-1){ $backtrace = debug_backtrace(); trigger_error('Invalid $limit `'.$limit.'` provided to '.__function__.'() in '. '`'.$backtrace[0]['file'].'` on line '.$backtrace[0]['line'].'. Expecting -1 or '. 'a positive integer', E_USER_WARNING); return $subject; } // No replacements necessary. Throw a notice as this was most likely not the intended // use. And, if it was (eg part of a loop, setting $limit dynamically), it can be // worked around by simply checking to see if $limit===0, and if it does, skip the // function call (and set $count to 0, if applicable). if($limit===0){ $backtrace = debug_backtrace(); trigger_error('Invalid $limit `'.$limit.'` provided to '.__function__.'() in '. '`'.$backtrace[0]['file'].'` on line '.$backtrace[0]['line'].'. Expecting -1 or '. 'a positive integer', E_USER_NOTICE); return $subject; } // Use str_replace() whenever possible (for performance reasons) if($limit===-1){ return str_replace($search, $replace, $subject, $count); } if(is_array($subject)){ // Loop through $subject values and call this function for each one. foreach($subject as $key => $this_subject){ // Skip values that are arrays (to match str_replace()). if(!is_array($this_subject)){ // Call this function again for $this_function = __FUNCTION__; $subject[$key] = $this_function( $search, $replace, $this_subject, $this_count, $limit ); // Adjust $count $count += $this_count; // Adjust $limit, if not -1 if($limit!=-1){ $limit -= $this_count; } // Reached $limit, return $subject if($limit===0){ return $subject; } } } return $subject; } elseif(is_array($search)){ // Only treat $replace as an array if $search is also an array (to match str_replace()) // Clear keys of $search (to match str_replace()). $search = array_values($search); // Clear keys of $replace, if applicable (to match str_replace()). if(is_array($replace)){ $replace = array_values($replace); } // Loop through $search array. foreach($search as $key => $this_search){ // Don't support multi-dimensional arrays (to match str_replace()). $this_search = strval($this_search); // If $replace is an array, use the value of $replace[$key] as the replacement. If // $replace[$key] doesn't exist, just an empty string (to match str_replace()). 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 $limit, if not -1 if($limit!=-1){ $limit -= $this_count; } // Reached $limit, return $subject if($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, to make proper replacement later on $search_len = strlen($search); // Loop until $search can no longer be found, or $limit is reached for($i=0;(($i<$limit)||($limit===-1));$i++){ // Replace $subject = substr_replace($subject, $replace, $pos, $search_len); // Increase $count $count++; // Get location of next $search $pos = strpos($subject, $search); // Break out of loop if $needle if($pos===false){ break; } } // Return new $subject return $subject; } } при <?php /** * Checks if $string is a valid integer. Integers provided as strings (eg '2' vs 2) * are also supported. * @param mixed $string * @return bool Returns boolean TRUE if string is a valid integer, or FALSE if it is not */ function valid_integer($string){ // 1. Cast as string (in case integer is provided) // 1. Convert the string to an integer and back to a string // 2. Check if identical (note: 'identical', NOT just 'equal') // Note: TRUE, FALSE, and NULL $string values all return FALSE $string = strval($string); return ($string===strval(intval($string))); } /** * Replace $limit occurences of the search string with the replacement string * @param mixed $search The value being searched for, otherwise known as the needle. 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, 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. * @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 ){ // Set some defaults $count = 0; // Invalid $limit provided. Throw a warning. if(!valid_integer($limit)){ $backtrace = debug_backtrace(); trigger_error('Invalid $limit `'.$limit.'` provided to '.__function__.'() in '. '`'.$backtrace[0]['file'].'` on line '.$backtrace[0]['line'].'. Expecting an '. 'integer', E_USER_WARNING); return $subject; } // Invalid $limit provided. Throw a warning. if($limit<-1){ $backtrace = debug_backtrace(); trigger_error('Invalid $limit `'.$limit.'` provided to '.__function__.'() in '. '`'.$backtrace[0]['file'].'` on line '.$backtrace[0]['line'].'. Expecting -1 or '. 'a positive integer', E_USER_WARNING); return $subject; } // No replacements necessary. Throw a notice as this was most likely not the intended // use. And, if it was (eg part of a loop, setting $limit dynamically), it can be // worked around by simply checking to see if $limit===0, and if it does, skip the // function call (and set $count to 0, if applicable). if($limit===0){ $backtrace = debug_backtrace(); trigger_error('Invalid $limit `'.$limit.'` provided to '.__function__.'() in '. '`'.$backtrace[0]['file'].'` on line '.$backtrace[0]['line'].'. Expecting -1 or '. 'a positive integer', E_USER_NOTICE); return $subject; } // Use str_replace() whenever possible (for performance reasons) if($limit===-1){ return str_replace($search, $replace, $subject, $count); } if(is_array($subject)){ // Loop through $subject values and call this function for each one. foreach($subject as $key => $this_subject){ // Skip values that are arrays (to match str_replace()). if(!is_array($this_subject)){ // Call this function again for $this_function = __FUNCTION__; $subject[$key] = $this_function( $search, $replace, $this_subject, $this_count, $limit ); // Adjust $count $count += $this_count; // Adjust $limit, if not -1 if($limit!=-1){ $limit -= $this_count; } // Reached $limit, return $subject if($limit===0){ return $subject; } } } return $subject; } elseif(is_array($search)){ // Only treat $replace as an array if $search is also an array (to match str_replace()) // Clear keys of $search (to match str_replace()). $search = array_values($search); // Clear keys of $replace, if applicable (to match str_replace()). if(is_array($replace)){ $replace = array_values($replace); } // Loop through $search array. foreach($search as $key => $this_search){ // Don't support multi-dimensional arrays (to match str_replace()). $this_search = strval($this_search); // If $replace is an array, use the value of $replace[$key] as the replacement. If // $replace[$key] doesn't exist, just an empty string (to match str_replace()). 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 $limit, if not -1 if($limit!=-1){ $limit -= $this_count; } // Reached $limit, return $subject if($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, to make proper replacement later on $search_len = strlen($search); // Loop until $search can no longer be found, or $limit is reached for($i=0;(($i<$limit)||($limit===-1));$i++){ // Replace $subject = substr_replace($subject, $replace, $pos, $search_len); // Increase $count $count++; // Get location of next $search $pos = strpos($subject, $search); // Break out of loop if $needle if($pos===false){ break; } } // Return new $subject return $subject; } } при <?php /** * Checks if $string is a valid integer. Integers provided as strings (eg '2' vs 2) * are also supported. * @param mixed $string * @return bool Returns boolean TRUE if string is a valid integer, or FALSE if it is not */ function valid_integer($string){ // 1. Cast as string (in case integer is provided) // 1. Convert the string to an integer and back to a string // 2. Check if identical (note: 'identical', NOT just 'equal') // Note: TRUE, FALSE, and NULL $string values all return FALSE $string = strval($string); return ($string===strval(intval($string))); } /** * Replace $limit occurences of the search string with the replacement string * @param mixed $search The value being searched for, otherwise known as the needle. 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, 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. * @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 ){ // Set some defaults $count = 0; // Invalid $limit provided. Throw a warning. if(!valid_integer($limit)){ $backtrace = debug_backtrace(); trigger_error('Invalid $limit `'.$limit.'` provided to '.__function__.'() in '. '`'.$backtrace[0]['file'].'` on line '.$backtrace[0]['line'].'. Expecting an '. 'integer', E_USER_WARNING); return $subject; } // Invalid $limit provided. Throw a warning. if($limit<-1){ $backtrace = debug_backtrace(); trigger_error('Invalid $limit `'.$limit.'` provided to '.__function__.'() in '. '`'.$backtrace[0]['file'].'` on line '.$backtrace[0]['line'].'. Expecting -1 or '. 'a positive integer', E_USER_WARNING); return $subject; } // No replacements necessary. Throw a notice as this was most likely not the intended // use. And, if it was (eg part of a loop, setting $limit dynamically), it can be // worked around by simply checking to see if $limit===0, and if it does, skip the // function call (and set $count to 0, if applicable). if($limit===0){ $backtrace = debug_backtrace(); trigger_error('Invalid $limit `'.$limit.'` provided to '.__function__.'() in '. '`'.$backtrace[0]['file'].'` on line '.$backtrace[0]['line'].'. Expecting -1 or '. 'a positive integer', E_USER_NOTICE); return $subject; } // Use str_replace() whenever possible (for performance reasons) if($limit===-1){ return str_replace($search, $replace, $subject, $count); } if(is_array($subject)){ // Loop through $subject values and call this function for each one. foreach($subject as $key => $this_subject){ // Skip values that are arrays (to match str_replace()). if(!is_array($this_subject)){ // Call this function again for $this_function = __FUNCTION__; $subject[$key] = $this_function( $search, $replace, $this_subject, $this_count, $limit ); // Adjust $count $count += $this_count; // Adjust $limit, if not -1 if($limit!=-1){ $limit -= $this_count; } // Reached $limit, return $subject if($limit===0){ return $subject; } } } return $subject; } elseif(is_array($search)){ // Only treat $replace as an array if $search is also an array (to match str_replace()) // Clear keys of $search (to match str_replace()). $search = array_values($search); // Clear keys of $replace, if applicable (to match str_replace()). if(is_array($replace)){ $replace = array_values($replace); } // Loop through $search array. foreach($search as $key => $this_search){ // Don't support multi-dimensional arrays (to match str_replace()). $this_search = strval($this_search); // If $replace is an array, use the value of $replace[$key] as the replacement. If // $replace[$key] doesn't exist, just an empty string (to match str_replace()). 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 $limit, if not -1 if($limit!=-1){ $limit -= $this_count; } // Reached $limit, return $subject if($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, to make proper replacement later on $search_len = strlen($search); // Loop until $search can no longer be found, or $limit is reached for($i=0;(($i<$limit)||($limit===-1));$i++){ // Replace $subject = substr_replace($subject, $replace, $pos, $search_len); // Increase $count $count++; // Get location of next $search $pos = strpos($subject, $search); // Break out of loop if $needle if($pos===false){ break; } } // Return new $subject return $subject; } }