In this article, you will learn how to get the count of matches of a pattern in PHP string. The preg_match_all() function in PHP returns the number of matches of a pattern that were found in a string and populates a variable with the matches that were found.
what is the syntax of the PREG_MATCH_ALL function in php?
preg_match_all(pattern, input, matches, flags, offset)| Parameter | Description |
|---|---|
| pattern | Required. Contains a regular expression indicating what to search for |
| input | Required. The string in which the search will be performed |
| matches | Optional. The variable used in this parameter will be populated with an array containing all of the matches that were found |
| flags | Optional. A set of options that change how the matches array is structured. One of the following structures may be selected: PREG_PATTERN_ORDER – Default. Each element in the matches array is an array of matches from the same grouping in the regular expression, with index 0 corresponding to matches of the whole expression and the remaining indices for subpattern matches.PREG_SET_ORDER – Each element in the matches array contains matches of all groupings for one of the found matches in the string.Any number of the following options may be applied:PREG_OFFSET_CAPTURE – When this option is enabled, each match, instead of being a string, will be an array where the first element is a substring containing the match and the second element is the position of the first character of the substring in the input.PREG_UNMATCHED_AS_NULL – When this option is enabled, unmatched subpatterns will be returned as NULL instead of as an empty string. |
| offset | Optional. Defaults to 0. Indicates how far into the string to begin searching. The preg_match() function will not find matches that occur before the position given in this parameter |
examples of the PREG_MATCH_ALL function
Example 1. In this example, we find all occurrences of “ain” in a string.
<?php
$str = "The rain in SPAIN falls mainly on the plains.";
$pattern = "/ain/i";
if(preg_match_all($pattern, $str, $matches)) {
print_r($matches);
}
?>
