In this article, you will learn how to replace an array of strings in PHP. The preg_replace_callback_array() function in PHP returns a string or an array of strings in which matches of a set of regular expressions are replaced with the return value of a callback function.
what is the syntax of the PREG_REPLACE_CALLBACK_ARRAY function in php?
preg_replace_callback_array(patterns, input, limit, count)| Parameter | Description |
|---|---|
| pattern | Required. An associative array which associates regular expression patterns to callback functions. The callback functions have one parameter which is an array of matches.The first element in the array contains the match for the whole expression while the remaining elements have matches for each of the groups in the expression. |
| input | Required. The string or array of strings in which replacements are being performed |
| limit | Optional. Defaults to -1, meaning unlimited. Sets a limit to how many replacements can be done in each string |
| count | Optional. After the function has executed, this variable will contain a number indicating how many replacements were performed |
examples of the PREG_REPLACE_CALLBACK_ARRAY function
Example 1. In this example, we show how many letters or digits are found in each word in a sentence.
<?php
function countLetters($matches) {
return $matches[0] . '[' . strlen($matches[0]) . 'letter]';
}
function countDigits($matches) {
return $matches[0] . '[' . strlen($matches[0]) . 'digit]';
}
$input = "There are 365 days in a year.";
$patterns = [
'/\b[a-z]+\b/i' => 'countLetters',
'/\b[0-9]+\b/' => 'countDigits'
];
$result = preg_replace_callback_array($patterns, $input);
echo $result;
?>
